101,958 research outputs found
Tropidoturris vizcondei Morassi & Bonfitto, 2013, sp. nov.
No full textTropidoturris vizcondei sp. nov. Figures 1. A–H Type material: Holotype (MNHN 26614). 4 Paratypes (2 from stn. CC 3175 (MNHN 26615); 1 from stn. CP 3143 (MNHN 26617); 1 from stn. CP 3133 (MNHN 26618); 1 (coated) from stn. CC 3175 (MZB 60071). Type locality: Mozambique Channel (Maputo transect), 25 ° 34 ’S 34 ° 11 ’E, 155– 165 m. Material examined: Mozambique Channel (Maputo transect): 25 ° 34 ’S 34 ° 11 ’E, 155– 165 m. [N/O “Vizconde de Eza” MAINBAZA, stn. CC 3175] (holotype and 3 paratypes); 25 ° 11 ’S 35 ° 10 ’E, 200– 201 m. [N/O “Vizconde de Eza” MAINBAZA, stn. CP 3133] (1 paratype); 23 ° 32 ’S 35 ° 46 ’E, 264– 277 m.[N/O “Vizconde de Eza” MAINBAZA, stn. CP 3143] (1 paratype). Description: Shell (fig. A–C) fusiform-biconic (b/l 0.37–0.39; a/l 0.49–0.54), with a high spire; base tapering, shallowly excavated. Protoconch of 1 ½ strongly convex whorls (fig. F–G) with a series of weak axial growth ribs at termination; under SEM (fig. H) the protoconch surface is seen to be sculptured by microscopic rows of spiral threads more evident on terminal part. Protoconch diameter: 0.75–0.90 mm. Teleoconch of up to 5 whorls sharply shouldered at mid-whorl height, sutural ramp broad, shallowly concave. First teleoconch whorl with a prominent peripheral cord; in some specimens a second weaker cord just below the peripheral one. Two prominent spiral cords on second whorl, increasing to 3 on antepenultimate and penultimate whorls (in some specimens with a fourth narrow spiral cord at level of abapical suture) (fig. D). Last whorl with 3–5 spiral cords; 11–14 cords on base and rostrum. Axial sculpture of fine to relatively prominent growth lines. No axial ribs. Under SEM (fig. E) the surface of sutural ramp and the interspaces, between spiral cords, are seen to be covered by microscopic rows of slightly wavy spiral threads. Aperture narrowly lanceolate, tapering slightly towards base, truncated posteriorly at sinus. Columella and parietal region weakly convex, columellar callus thin. Siphonal canal short, shallowly notched. Outer lip thin. Anal sinus deep, relatively broad, occupying entire sutural ramp. Color uniform pale orange-yellow. Dimensions: Holotype: 11.1 x 4.3 mm, aperture height 6.0 mm; largest paratype (CP 3143): 13.2 x 5.1 mm, aperture height 7.2 mm; smallest paratype (CC 3175): 9.7 x 3.8 mm, aperture height 4.8 mm. Etymology. Named after the research vessel “Vizconde de Eza” used in the dredging of the type material. Remarks. Tropidoturris vizcondei sp. nov. is comparable only to Tropidoturris simplicicingula simplicicingula (Barnard, 1958) and T. planilirata Kilburn, 1986 in the complete lack of axial sculpture, but otherwise differs distinctly from both species mainly in its smaller dimensions (up to 13.2 mm versus 19.8 in T. simplicicingula simplicicingula and 16.8 mm in T. planilirata), and in possessing fewer teleoconch whorls (up to 5 whorls versus 6 in T. simplicicingula simplicicingula and 5 ½ in T. planilirata) sculptured by fewer spiral cords. In particular, Tropidoturris vizcondei sp. nov. has 3–4 and 3–5 spiral cords on penultimate and last whorl respectively while T. simplicicingula simplicicingula and T. planilirata have respectively 6–10 and 4–5 spiral cords (excluding peripheral cord) on abapical part of penultimate whorl. Furthermore, T. planilirata has 1–2 spiral cords on sutural ramp which are totally absent in T. vizcondei. The shell of T. vizcondei is uniform pale orange-yellow while that of both T. planilirata and T. simplicicingula simplicicingula is more vividly patterned with brown blotches. Finally, in Tropidoturris vizcondei the anal sinus seems broader than in any of its described congeners.Published as part of Morassi, Mauro & Bonfitto, Antonio, 2013, Four new African turriform gastropods (Mollusca: Conoidea), pp. 271-280 in Zootaxa 3710 (3) on page 273, DOI: 10.11646/zootaxa.3710.3.5, http://zenodo.org/record/22015
Teretia tavianii Morassi & Bonfitto, 2015, sp. nov.
No full textTeretia tavianii sp. nov. Figures 2.A–G Type material. Holotype (MZB 60097) and two paratypes (paratype 1 MZB 60098 (coated); paratype 2 MNHN IM- 2000-28378). Type locality. Gulf of Aden (Indian Ocean), 11 º 55 ' 95 "N, 44 º 22 ' 70 "E to 11 º 55 ' 82 "N, 44 º 22 ' 53 "E, 795–810 m], September 1992 [N/ O “Marion Dufresne”, RED SED 92, stn 1]. Material examined. Three dd (holotype and two paratypes) from the type locality. Description. Shell (Figs. 2.A–C) widely fusiform (b/l 0.46; a/l 0.50) with high spire, strongly excavated base and relatively long anterior canal. Teleoconch up to about 3 ½ whorls, with shallowly impressed, linear suture. Subsutural ramp rather wide, concave. Spiral sculpture on first teleoconch whorl consisting of a prominent peripheral cord below mid-height of the whorl and two closely spaced weak spiral cords bordering abapical part of subsutural ramp (the abapical one much stronger). On subsequent whorls a second cord develops at level of abapical suture; last whorl with one spiral thread in the interpace between two cords. Adapical part of subsutural ramp with a weak spiral cord near suture. Last whorl with six and nine spiral cords on base and rostrum respectively. Teleoconch whorls sculptured by fine axial growth lines forming relatively strong, widely spaced, arcuate plicules on subsutural ramp, rendering somewhat nodulous the spiral thread bordering adapical suture. Under SEM, the surface is seen to be sculptured by microgranules (Fig. 2.D). Aperture lanceolate, outer lip thin. Anal sinus deep, narrow, asymmetrical, its deepest point on subsutural ramp (Fig. 2.B). Protoconch of three whorls; first whorl tilted with microgranules arranged in spiral rows, subsequent whorls with diagonally cancellate sculpture terminating a short distance above abapical suture where fine slightly prosocline riblets occur. Maximum diameter about 0.38 mm. Shell white, protoconch brown. Dimensions: Holotype 3.2 x 1.5 mm, aperture height 1.6 mm. Remarks. Teretia tavianii sp. nov. differs from the Southern Africa Teretia acus (Barnard, 1958) in having fewer, less prominent, spiral cords (two versus three on spire whorls) and in number of protoconch whorls (3 rather than 4 ½). T.tavianii sp. nov. differs from T. anceps and T. teres in possessing fewer, less prominent cords (two versus respectively 4–5 and 3–4 main cords on spire whorls; compare Figs. 2.C–D and Fig. 3.B–C) and in protoconch features (compare Figs. 2.E–G with Figs. 3. D–F). More in detail, T. tavianii sp. nov. has fewer protoconch whorls (3 rather than 4 – 4 ½) and while in the new species the diagonally cancellate sculpture tends to be restricted to whorl periphery, in both T. anceps and T. teres it occurs on whorl surface except for a narrow area near adapical suture (compare Fig. 2.E with Fig. 3.D). Teretia fusianceps Nordsieck, 1972 is distinguished from T. tavianii sp. nov. in having more prominent spiral cords and a more narrowly fusiform shell. Etymology. Named after Marco Taviani, Geologist of Institute of Marine Science, National Research Council ISMAR-CNR, that made possible the participation of the one of the authors (AB) to the cruise RED SED ’ 92.Published as part of Morassi, Mauro & Bonfitto, Antonio, 2015, New Indo-Pacific species of the genus Teretia Norman, 1888 (Gastropoda: Raphitomidae), pp. 560-570 in Zootaxa 3911 (4) on pages 564-565, DOI: 10.11646/zootaxa.3911.4.5, http://zenodo.org/record/24027
Rotors on Active Magnetic Bearings: Modeling and Control Techniques
No full textIn the last decades the deeper and more detailed understanding of rotating machinery dynamic behavior facilitated the study and the design of several devices aiming at friction reduction, vibration damping and control, rotational speed increase and mechanical design optimization. Among these devices a promising technology is represented by active magnetic actuators which found a great spread in rotordynamics and in high precision applications due to (a) the absence of all fatigue and tribology issues motivated by the absence of contact, (b) the small sensitivity to the operating conditions, (c) the wide possibility of tuning even during operation, (d) the predictability of the behavior. This technology can be classified as a typical mechatronic product due to its nature which involves mechanical, electrical and control aspects, merging them in a single system. The attractive potential of active magnetic suspensions motivated a considerable research effort for the past decade focused mostly on electrical actuation subsystem and control strategies. Examples of application areas are: (a) Turbomachinery, (b) Vibration isolation, (c) Machine tools and electric drives, (d) Energy storing flywheels, (e) Instruments in space and physics, (f) Non-contacting suspensions for micro-techniques, (g) Identification and test equipment in rotordynamics. This chapter illustrates the design, the modeling, the experimental tests and validation of all the subsystems of a rotors on a five-axes active magnetic suspension. The mechanical, electrical, electronic and control strategies aspects are explained with a mechatronic approach evaluating all the interactions between them. The main goals of the manuscript are: • Illustrate the design and the modeling phases of a five-axes active magnetic suspension; • Discuss the design steps and the practical implementation of a standard suspension control strategy; • Introduce an off-line technique of electrical centering of the actuators; • Illustrate the design steps and the practical implementation of an online rotor selfcentering control technique. The experimental test rig is a shaft (Weight: 5.3 kg. Length: 0.5 m) supported by two radial and one axial cylindrical active magnetic bearings and powered by an asynchronous high frequency electric motor. The chapter starts on an overview of the most common technologies used to support rotors with a deep analysis of their advantages and drawbacks with respect to active magnetic bearings. Furthermore a discussion on magnetic suspensions state of the art is carried out highlighting the research efforts directions and the goals reached in the last years. In the central sections, a detailed description of each subsystem is performed along with the modeling steps. In particular the rotor is modeled with a FE code while the actuators are considered in a linearized model. The last sections of the chapter are focused on the control strategies design and the experimental tests. An off-line technique of actuators electrical centering is explained and its advantages are described in the control design context. This strategy can be summarized as follows. Knowing that: a) each actuation axis is composed by two electromagnets; b) each electromagnet needs a current closed-loop control; c) the bandwidth of this control is depending on the mechanical airgap, then the technique allows to obtain the same value of the closed-loop bandwidth of the current control of both the electromagnets of the same actuation axis. This approach improves performance and gives more steadiness to the control behavior. The decentralized approach of the control strategy allowing the full suspensions on five axes is illustrated from the design steps to the practical implementation on the control unit. Furthermore a selfcentering technique is described and implemented on the experimental test rig: this technique uses a mobile notch filter synchronous with the rotational speed and allows the rotor to spin around its mass center. The actuators are not forced to counteract the unbalance excitation avoiding saturations. Finally, the experimental tests are carried out on the rotor to validate the suspension control, the off-line electrical centering and the selfcentering technique. The numerical and experimental results are superimposed and compared to prove the effectiveness of the modeling approach
Acamptodaphne solomonensis Morassi & Bonfitto 2010, new species
No full textAcamptodaphne solomonensis new species Figures 1. G–O Type material: Holotype MNHN 22301. Paratypes: 1 MNHN 22302, 1 MZB 45712, 1 ZRC 2978. Type locality: Solomon Islands, 08°21.4’S 160°41.8’E. Material examined: Solomon Islands: 08°21.4’S 160°41.8’E, 194–286 m [N/O “ Alis ” SALOMON 1 Stn DW 1768] (holotype, 1 paratype at MNHN and 1 paratype at MZB); 08°20.4’S 160°40.6’E, 290–303m, [N/ O Alis SALOMON 1 Stn DW 1769] (1 juv. paratype at ZRC). Description: Shell fusiform-biconic (b/l 0.44–0.47; a/l 0.49–0.53). Teleoconch consisting of 4.5–5.2 whorls sharply angulated at one-third of whorl height on earlier whorls; angulation slightly weaker and near middle on last two spire whorls. Last whorl strongly excavated with a relatively long neck. Whorls separated by a deep, narrowly channelled suture. Sutural ramp wide, shallowly concave. Axial sculpture consisting of short, prominent, opisthocline ribs, with wider interspaces, extending from lower suture to peripheral angle where they are abruptly truncated and form prominent tubercles. Penultimate whorl with 16–19 ribs; axial ribs weaker and restricted to periphery on last whorl, becoming obsolete on latter part of the whorl. Spiral sculpture commencing as a subsutural thread and a prominent cord, forming the peripheral angulation, joined on second whorl by a weaker cord anteriorly. On subsequent whorls, suture is margined by two threads forming a weak subsutural fold, while additional 1–2 spiral cords develop below the peripheral cord; interstices between cords with 1–3 spiral threads on last two whorls. Sutural ramp lacking spirals on first whorl, bearing 6–8 threads on later whorls. Base sculptured by 26–27 spiral elements consisting of cords and threads of variable strength. Whorls covered by dense, rough collabral growth lines particularly evident on sutural ramp where are weakly frilled and sinuous in conformity with the anal sinus in outer lip; growth lines forming small, axially elongate tubercles on subsutural fold and small nodules at points of intersections with spiral cords. Under SEM, entire shell surface is seen to be covered by spiral rows of microscopic granules. Aperture lanceolate. Columella nearly straight above, distinctly curved to left below. Labial callus thin, sculptured by microscopic rows of prickly nodules in its interior part (fig. 2L). Siphonal canal relatively long (for genus), oblique and relatively wide. Anal sinus moderately deep, broadly reversed L-shaped, with its apex below middle of sutural ramp. Protoconch domed of 1.5–1.8 whorls covered with minute, dense spiral threads rendered granulose where crossed by even finer axial threads; last whorl with a few close, arcuate, axial plicules near termination. Protoconch breadth: 0.43–0.56 mm. Teleoconch white, protoconch pale buff. Dimensions: Holotype 8.2 x 3.6 mm, aperture height 4.0 mm; largest paratype: 7.2 x 3.2 mm, aperture height 3.8 mm; smallest paratype: 5 x 2,6 mm, aperture height 2,8 mm. Remarks: This species is readily distinguished from its congeners in having a fusiform-biconic rather than biconic shell, with a strongly concave left side of the base, and a paucispiral protoconch (figs. 1N–O). Etymology: solomonensis refers to the fact that this species is described from Solomon Islands.Published as part of Morassi, M. & Bonfitto, A., 2010, New raphitomine gastropods (Gastropoda: Conidae: Raphitominae) from the South-West Pacific, pp. 54-68 in Zootaxa 2526 on pages 57-5
A multi-purpose control and power electronic architecture for active magnetic actuators
No full textThis paper shows the results related with the design and implementation of a multi-purpose electronic architecture used to drive magnetic actuators by means of a three-phase independent-legs module in place of the commonly used H-bridge modules. The typical application is the magnetic actuators drive used in active magnetic bearings. The architecture is composed of a control unit with a floating point Digital Signal Processor (DSP), a power board with six independent phase legs and a carrier board to interconnect them. When more than one module is required by the application, the communication between them is guaranteed by means of CAN bus interconnection. The proposed system allows to drive two pairs of opposite electromagnets, such as those typically used to control active magnetic bearings. The study is motivated by the opportunity of reducing the amount of power and control electronic components resulting in a more straightforward, efficient and cost reduction desig
Teretia sysoevi Morassi & Bonfitto, 2015, sp. nov.
No full textTeretia sysoevi sp. nov. Figures 1.L–T Type material. Holotype (MNHN IM- 2000-28375) and two paratypes (paratype 1 MNHN IM- 2000-28377 (coated); paratype 2 MZB 60096). Type locality. Wallis & Futuna Islands, 14 °19,6'S 178 °06,7'E, 419–425 m [MUSORSTOM 7 stn DW 507], 11 May 1992. Material examined. Wallis & Futuna Islands, 14 °19,6'S 178 °06,7'E, 419–425 m [MUSORSTOM 7 stn DW 507], 11 May 1992 (1 dd, holotype); New Caledonia: 18 °48,20’S 163 °10,80’E, 720 m [MUSORSTOM 4 stn DC 168] 16 September 1985 (1 dd, paratype 1); Loyalty Ridge: 23 ° 54.46 S 169 ° 49.15 E, 699–715 m [N/ O “Alis” BATHUS 3 stn DW 786], Bouchet, Richer & Warén coll. 25 November 1993 (1 dd, paratype 2). Description. Shell (Figs. 1.L– O) fusiform (b/l 0.39; a/l 0.38) with high spire, strongly excavated base and relatively short anterior canal. Teleoconch of five whorls (six in paratypes) with shallowly impressed, linear suture. Subsutural ramp wide, moderately deeply concave. Earlier two teleoconch whorls with a prominent peripheral cord below mid- height of the whorl and two weak cords bordering abapical part of subsutural ramp (the abapical one bisected). On third whorl a second main spiral cord develops at level of abapical suture increasing in strength on subsequent whorls (Fig. 1.P). In one paratype the second main cord develops from first whorl onwards. Last whorl with a third main spiral cord near abapical suture and one weak cord in the interspace between peripheral and second main cords. Last whorl with 19 spiral cords on base and rostrum. Subsutural ramp lacking spiral sculpture (holotype) or with up to four low threads (paratypes) on later two whorls. Teleoconch whorls sculptured by fine axial growth lines forming weak, irregularly spaced, arcuate plicules on subsutural ramp (Fig. 1.P). Under SEM (Fig. 1.R), surface is seen to be covered by a sculpture of dense microscopic pustules. Aperture lanceolate, outer lip thin. Anal sinus very deep, narrow, asymmetrical; its deepest point on sutural ramp. Protoconch (Figs. 1.S–T) of 2 ½+ whorls; tip missing, remaining whorls with diagonally cancellate sculpture terminating a short distance above abapical suture where fine slightly prosocline riblets occur. Maximum diameter about 0.48 mm. Colour of teleoconch whitish to pale buff, protoconch light brown. Dimensions: Holotype 5.8 x 2.3 mm, aperture height 2.2 mm. Largest Paratype (MZB): 7.5 x 2.9 mm, aperture height 3.1 mm. Remarks. Teretia sysoevi sp. nov. is morphologically similar to Teretia neocaledonica sp. nov. from which it differs in numerous details of shell morphology. Teretia sysoevi sp. nov. has more numerous teleoconch whorls (5–6 versus 4 – 4 ¾), a more deeply concave subsutural ramp lacking spiral cords near adapical suture and the growth lines consist of very fine lines rather than axial plicules (compare Figs. 1.E–F with Fig. 1.P–Q). Under SEM, T. sysoevi has a distinctive sculpture of dense microscopic pustules (Fig. 1.R) while T. neocaledonica has sparser granules (Fig. 1.G). The two species further differ in colour: T. sysoevi has a whitish to pale buff shell lacking the brown band typically occurring on periphery of spire whorls of T. neocaledonica. Etymology. Named after Alexander Sysoev of Zoological Museum, Moscow State University (Russia) in recognition to his contribution to our knowledge of the turriform gastropods.Published as part of Morassi, Mauro & Bonfitto, Antonio, 2015, New Indo-Pacific species of the genus Teretia Norman, 1888 (Gastropoda: Raphitomidae), pp. 560-570 in Zootaxa 3911 (4) on pages 562-564, DOI: 10.11646/zootaxa.3911.4.5, http://zenodo.org/record/24027
Buchema shearmani Morassi & Bonfitto, 2013, sp. nov.
No full textBuchema shearmani sp. nov. Figures 1. L–P Type material. Holotype (MZB 60074) and 2 paratypes (MZB 60075); 1 paratype (MNHN-IM- 2012-2533) Type locality. Offshore Mogadishu (Somalia), trawled by local fishermen at unknown depth in 1989–1990. Material examined. The type material. Description. Shell (fig. L–M) claviform (b/l 0.34–0.35; a/l 0.33–0.35), with a high, slightly inflated spire, blunt apex and subcylindrical last whorl. Protoconch (fig. O) bluntly conical of 1 ¾– 2 whorls; first 1 ½ sculptured by stout axial ribs; last portion with thinner, closely spaced ribs crossed by spiral threads. Protoconch diameter: 0.74–0.86 mm. Teleoconch of 5 ½– 5 ¾ convex whorls, with periphery at ⅔–¾ of whorl height; subsutural margin forming a weak cord. Sculpture of prominent, opisthocline axial ribs crossed by low, flat-topped spiral cords becoming swollen over axial ribs. Axial ribs straight, but slightly arcuate over sutural ramp where they are weaker, narrower than their intervals, projecting most at periphery, fading across base at level of parietal region. Eight to 9 axial ribs on penultimate whorl, 9–10 on last whorl. Spiral sculpture of three main spiral cords, the upper one rather more slender than the others. Additional 1–2 cords, weaker than others, develop on later two teleoconch whorls. Interspaces between spiral cords sculptured by low spiral threads which decussate dense, fine axial lines (fig. P). On later two teleoconch whorls about 3–7 spiral threads, varying in strength, in each interval between spiral cords. Sutural ramp with a low, feeble to nearly obsolete spiral lira preceded by 2–5 threads and followed by others 6–7. Aperture narrow, quadrangular. Columella straight, with relatively thick callus, its outer edge not raised; parietal pad forming a prominent nodule, which greatly restricts entrance of anal sinus. Outer lip with a slight stromboid notch in the abapical part, almost straight in lateral view, with a cutting edge, preceded by a varicoid rib. Anal sinus moderately deep, C-shaped. Color: a) brownish orange with ivory white spiral cords where they cross the axials. Interior of the aperture orange-yellow; b) uniform dark brown. Dimensions: Holotype 9.9 x 3.5 mm; aperture 3.5 mm; largest paratype (MZB): 10.6 x 3.6 mm, aperture 3.5 mm. Etymology. Named after professor John K. G. Shearman (1931–2003) well known art historian. Remarks. The new species differs distinctly from all its described congeners. Of the five Buchema species from Puerto Rico proposed by Corea (1934), Buchema shearmani sp. nov. superficially resembles in general features the type species Carinodrillia (Buchema) tainoa Corea, 1934 but the latter is larger (14.2 mm versus up to 10.6 mm in length), with a much broader and stronger shoulder. Furthermore, shell colour of B. shearmani varies from brownish orange with ivory white spiral cords to uniform dark brown while B. tainoa has a brown shell with interspaces darker than the axial ribs and “summit of the whorls marked by brown spots separated by lightercolored intervals” (Corea, 1934). Buchema shearmani differs from the southern Africa Buchema dichroma Kilburn, 1988 in its much narrower shell (b/l 0.34–0.35 versus 0.43–0.47), sculptured by much fewer and weaker spiral cords and very different colour pattern (brownish orange with ivory white spiral cords or uniform dark brown versus bicolored yellow and violet) (Kilburn, 1988: 244, figs. 188–189). Buchema dichroma further differs from both Buchema shearmani and other Buchema species described by Corea (1934) in details of the protoconch which consists of smooth whorls except for few weak axial riblets crossed by feeble spiral striae near termination (Kilburn, 1988: 246). Actually the morphologically closest species is probably Crassispira soamanitraensis Bozzetti, 2008, from Madagascar, which is comparable in dimensions and color and may prove referable to the genus Buchema. However, Crassispira soamanitraensis differs from the new species in having stronger, more closely spaced spiral cords.Published as part of Morassi, Mauro & Bonfitto, Antonio, 2013, Four new African turriform gastropods (Mollusca: Conoidea), pp. 271-280 in Zootaxa 3710 (3) on pages 276-277, DOI: 10.11646/zootaxa.3710.3.5, http://zenodo.org/record/22015
Teretia neocaledonica Morassi & Bonfitto, 2015, sp. nov.
No full textTeretia neocaledonica sp. nov. Figures 1.A–J Type material: Holotype (MNHN IM- 2000-28374) and 22 paratypes (21 paratypes MNHN IM- 2000-28376; one paratype MZB 60095) Type locality: South of New Caledonia, Bank Eponge (mont 8), 24 ° 55 S 168 ° 22 E, 502–532 m [N/ O “Alis” SMIB 8 stn DW 146-147]. Material examined: South of New Caledonia: Bank Eponge (mont 8), 24 ° 55 S 168 ° 22 E, 502–532 m [N/ O “Alis” SMIB 8 stn DW 146-147] (23 dd, holotype and 22 paratypes); Bank Eponge (mont 8), 24 ° 55.20 'S 168 ° 21.73 'E, 514–522 m [N/ O “Alis” SMIB 8 stn DW 146] 27 January 1993 (1 dd). Coral Sea, Bank CAPEL: 24 ° 44.83 S 159 ° 41.00 E, 285 m [N/ O “Coriolis” MUSORSTOM 5 stn DW 274], Bouchet, Metivier& Richer coll. 0 9 October 1986 (1 dd). New Caledonia, Loyalty Ridge: 24 °45,55'S 170 °07,40' E, 850–855 m [N/ O “Alis” BATHUS 3 stn DW 780], Bouchet, Richer &Warén coll. 24 November 1993 (1 dd); 23 °47,50'S 169 °48,75'E, 731–751 m [N/ O “Alis” BATHUS 3 stn DW 793], Bouchet, Richer &Warén coll. 26.11. 1993 (1 dd); 23 °35,12' S 169 °36,73' E, 655 m [N/ O “Alis” BATHUS 3 stn DW 800], Bouchet, Richer &Warén coll. 26 November 1993 (1 dd); 23 °39,39'S 167 °58,94'E, 650–730 m [N/ O “Alis” BATHUS 3 stn DW 809], 27 December 1993 (1 dd). Description. Shell (Figs. 1.A–D) fusiform (b/l 0.41; a/l 0.33) with high spire, strongly excavated base and relatively long anterior canal. Teleoconch up to about 4 ¾ whorls (four in most specimens) with shallowly impressed, linear suture. Subsutural ramp wide, shallowly concave. Earlier two teleoconch whorls with a prominent peripheral cord below mid- height of the whorl and two closely spaced weak cords bordering abapical part of subsutural ramp. On third whorl the adapical cord on subsutural ramp becomes bisected and a second main cord develops at level of abapical suture (Figs. 1.E–F). Last whorl with a third main cord and additional weak cords: one on abapical part of subsutural ramp and 1–2 in each interspace between main spiral cords. Last whorl with 26 spiral cords on base and rostrum. Subsutural ramp with two spiral threads bordering adapical suture. Teleoconch whorls sculptured by fine axial growth lines forming weak, widely spaced, arcuate plicules on subsutural ramp, rendering somewhat nodulous the two spiral threads bordering adapical suture (Fig. 1.E). Under SEM (Figs. 1.E–G), surface is seen to be covered by a sculpture of microgranules. Aperture lanceolate, outer lip thin. Anal sinus very deep, narrow, asymmetrical, with its deepest point on sutural ramp (Fig. 1.D). Protoconch (Figs. 1.H–J) tall, narrowly conical of 3 ½– 4 whorls; first whorl tilted with microgranules arranged in spiral rows, subsequent whorls with diagonally cancellate sculpture terminating a short distance above abapical suture where fine slightly prosocline riblets occur. Maximum diameter about 0.48 mm. Shell yellowish-white to white with a yellowish-brown band on periphery of whorls: weak to absent on first whorl, distinct on penultimate and last whorls, and (in some specimens) also at level of limit base-rostrum. Some specimens with few weak, light brown, subsutural blotches on last whorl. Protoconch brown. Dimensions: Holotype 5.9 x 2.4 mm, aperture height 2.6 mm. Remarks. Teretia neocaledonica sp. nov. resembles the Miocene-Pliocene T. turritelloides (Bellardi, 1847) in shape and disposition of spiral cords but differs from the latter in details of protoconch and teleoconch sculpture. More in detail, Teretia neocaledonica sp. nov. has slightly fewer protoconch whorls than T. turritelloides (3.5–4 versus 4–4.5) with a different sculpture; in the new species the axial riblets strongly decussate on periphery of each protoconch whorl, particularly on last whorl, while in T. turritelloides decussation occurs on whorl surface except for a narrow area near adapical suture (see Brunetti & Vecchi, 2003: plate 3, fig. 3). Furthermore, judging from the syntype of T. turritelloides from the Pliocene of Colli Astesi, figured by Ferrero Mortara et al. (1981: pl. 18, fig. 6 a– 6 b), the fossil species has a secondary sculpture more prominent than T. neocaledonica. The Italian Pliocene Teretia elegantissima (Foresti, 1868) differs distinctly from the new species in having a much more prominent peripheral keel formed by numerous (4–6) closely spaced spiral cords (fig. 3.G). Etymology. Neocaledonica = alluding to the fact that the type material was dredged off New Caledonia.Published as part of Morassi, Mauro & Bonfitto, Antonio, 2015, New Indo-Pacific species of the genus Teretia Norman, 1888 (Gastropoda: Raphitomidae), pp. 560-570 in Zootaxa 3911 (4) on page 562, DOI: 10.11646/zootaxa.3911.4.5, http://zenodo.org/record/24027
Three new marginellid gastropods (Muricoidea: Marginellidae: Granunilinae) from the Red Sea and Djibouti (Gulf of Aden)
No full textA new species of Marginellopsis Bavay, 1911, Marginellopsis herosae n. sp. and two new species of Granulina Jousseaume, 1888, Granulina morassii n. sp. and Granulina boyeri n. sp. are described and illustrated from the Red Sea and Djibouti. Marginellopsis herosae n.sp. represents the first Indo-Pacific record of a genus previously known by only one species from Cuba, Caribbean Sea. The biogeographic relevance of this finding and the possible Tethyan origin of the genus Marginellopsis is suggested. Micrographs of the type specimens of Granulina isseli (G. Nevill & H. Nevill, 1875), Granulina mariei (Crosse, 1867), Granulina cartwrighti (Sowerby, 1915) and Marginellopsis serrei Bavay, 1911 are provided
Notes on the fossil chitons. 3. A new species of Leptochiton (Mollusca: Polyplacophora) from the Pleistocene of South Italy
No full textLeptochiton serenae n.sp. is described from Early Pleistocene clayey deposits at Cutrufiano and Isola del Campo,near Lecce (Southern Italy). The new species has a distinctive sculpture on the tegmentum. It was compared with the five species of Leptochiton known from the Pleistocene of Southern Italy, and with two living North Atlantic species, Leptochiton asellus (Gmelin , 1791) and Leptochiton arcticus 8G.O.Sars, 1878), sharing some similarities with the new species
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