Taxonomic study on the molluscs collected in Marion-Dufresne expedition (MD 55) to SE Brazil: Xenophoridae, Cypraeoidea, mitriforms and Terebridae (Caenogastropoda) Simone, Luiz Ricardo L. Cunha, Carlo M. Zoosystema 2012 2012-12-31 34 4 745 781 59QG5 Simone & Cunha, 2012 Simone & Cunha 2012 [800,1020,1292,1319] Gastropoda Costellariidae Turricostellaria Animalia Neogastropoda 15 760 Mollusca species ovir sp. nov.  ( Fig. 6A-D)   TYPE MATERIAL. — Holotype: Brazil, Espírito Santo, off Itaúnas, continental slope of Abrolhos, 18°58’S, 37°48’W, 1200 mdepth, MNHN25237 ( Fig. 6A, B) ( MD55, stn DC78, Bouchet, Leal & Métivier coll., 27. V.1987). Paratypes: same data as holotype, MZSP102860, 1 shell ( Fig. 6C, D). — Off Conceição da Barra, 18°59’S, 37°47’W, 1540-1550 mdepth, MZSP102860, 1 shell ( Fig. 6C, D) (stn CB70, 26. V.1987).   TYPELOCALITY. — Brazil, Espírito Santo, off Itaúnas, continental slope of Abrolhos, 18°58’S, 37°48’W, 1200 mdepth ( MD55, stn DC78).  DISTRIBUTION. — Espírito Santocontinental slope.  ETYMOLOGY. — The specific epithet is derived from the native Parintintin language, from “ovir”, meaning sharp pointed, arrow-like ( Betts 1981), an allusion to the outline of the shell shape.  DIAGNOSIS. — Shell up to 10 mm, elongated (length c.3 times width). Sculpture axial, strong, slightly prosocline; shoulder absent. Protoconch blunt, mammillate, of two whorls. Aperture c.⅓ shell length. Canal narrow, relatively elongated.  DESCRIPTION Shell:size up to 10 mm, outline somewhat turriform; width c.35% of length. Colour uniform white ( Fig. 6A-C); surface opaque. Protoconch blunt, mammillate, comprising c.6% of shell length and c.16% of shell width; about two rounded, smooth, glossy whorls; suture shallow unclear ( Fig. 6D); transition with teleoconch unclear. Spire c.55% of shell length; spire angle c.30°. Teleoconch up to 6.5 whorls; each whorl lacking shoulder in last whorls ( Fig. 6A, B), and having shallow shoulder located below upper quarter of each whorl; remaining profile almost straight. Sculpture strong, uniform axial threads, slightly prosocline (angle c.10° in relation to shell longitudinal axis), from suture to suture; small node on shoulder in first teleoconch whorls ( Fig. 6C, D); c. 12 inpenultimate whorl; interspaces of axial threads roundly concave, as wide as threads. Ventral region of body whorl lacking spiral threads in anterior third ( Fig. 6A). Aperture elliptic, almost vertical; comprising c.30% of shell length and c.38% of shell width. Outer lip simple, rounded, lacking folds ( Fig. 6A, B). Inner lip weakly concave, callus shallow, upper third c.30° in relation to longitudinal shell axis; four oblique folds uniformly distributed in middle region, comprising c.70% of inner lip area; upper folds larger, diminishing up to inconspicuous fourth fold flanking canal ( Fig. 6A, C). Canal narrow, pointed, projected forwards along c.13% of shell length; with c.30% of aperture width. Dorsal surface of canal with pair of oblique, low folds as continuation of two upper columellar folds ( Fig. 6B). No umbilicus.  MEASUREMENTS (inmm). — Holotype: 9.9 × 3.6; paratype MZSP 102860: 5.2 × 2.5. HABITAT. — Sandy-mud bottoms, 1200-1550 mdepth.  DISCUSSION ON  TURRICOSTELLARIASPECIES The genus  Turricostellariawas coined to hold two Venezuelan, deep-water species with “tabulate whorls and scalariform appearance” ( Petuch 1987: 108), resembling a turrid. Despite some authors have considered it synonym of  Vexillum(e.g., Rosenberg 2010), it appears to be sufficiently distinct to be considered valid. It encompasses, beyond the two originally described species, at least another four species described herein, representing a deep-water taxon with turriform-like species, lacking spiral sculpture. Despite the protoconch was never mentioned in the original description of  Turricostellaria, neither afterwards, the species described here show that the structure can divide the species of the genus into two groups: one with paucispiral protoconch (  T. amphissa n. sp.and  T. ovir n. sp.– Figs 5B-D; 6C) and the other with multispiral protoconch (  T. jukyry n. sp.and  T. apyrahi n. sp.– Fig. 5I, N). There is no indication of the protoconch of  T. leonardhilli Petuch, 1987and  T. lindae Petuch, 1987; in the figures the structure appears eroded or paucispiral. The protoconch of  T. amphissa n. sp.is the shortest and widest, with a flattened suture; that of  T. ovir n. sp.is slightly longer and pointed, with suture slightly clearer. The protoconch of  T. jukyry n. sp.is the longest, bearing four whorls with deep suture; that of  T. apyrahi n. sp.has three whorls and is blunter.Additionally, those multispiral protoconch-bearing species have it in a pale brown colour, distinct from the remaining whitish colour of the teleoconch; this does not happen in the species with paucispiral protoconch.   Turricostellaria amphissa n. sp.is the shortest and most inflated of the genus; it is also the smallest ( c. 5 mm) and has the thinnest shell walls, being translucent. These are the main distinctions of the species.  Turricostellaria ovir n. sp.is the most elongated and sharpest of the genus, in this aspect it resembles  T. lindae, differing in lacking a developed shoulder and by the whorls much more elongated. The most difficult distinction is between  T. jukyry n. sp.and  T. apyrahi n. sp.Beyond the different protoconch mentioned above,  T. jukyry n. sp.has the shoulder more distinct, mainly in the first teleoconch whorls ( Fig. 5G, K), and the sculpture in this region is more developed and uniform than that of  T. apyrahi n. sp.The colour of  T. apyrahi n. sp.is more uniform, while that of  T. jukyry n. sp.is in yellow bands. The body whorl of  T. apyrahi n. sp.tends to be wider than expected for a uniform spiral growth ( Fig. 5Q, R), which does not happen in  T. jukyry n. sp.The aperture of  T. jukyry n. sp.is slightly shorter and more rounded, and the upper region of inner lip slightly more horizontal than that of  T. apyrahi n. sp.The axial sculpture is also distinctive, as that of  T. jukyry n. sp.tends to be more uniform and strong ( Fig. 5H, K) than that of  T. apyrahi n. sp., which lacks the axial sculpture in the last whorls ( Fig. 5L, Q).    Turricostellaria apyrahi n. sp.is the most similar to the Venezuelan  T. leonardhilli; it differs in having a more elongated outline and whorls, axial sculpture more developed, aperture slightly ampler, body whorl wider, and, mainly, the multispiral and pointed protoconch. The species also resembles  Latiromitra bairdii(Dall, 1889), from North Carolina( 965 mdepth); it differs in being shorter and wider, in having the aperture wider and longer, and the sculpture more developed.  Turricostellaria ovir n. sp.still differs from  T. leonardhilliin being more elongated, in having a small subsutural shoulder, more straight whorls profile, narrower body whorl and axial sculpture much more developed. MZSP 17 762 MZSP 102860 2 holotype