Clathrodrillia colombiana, Fallon, Phillip J., 2016

Fallon, Phillip J., 2016, Taxonomic review of tropical western Atlantic shallow water Drilliidae (Mollusca: Gastropoda: Conoidea) including descriptions of 100 new species, Zootaxa 4090 (1), pp. 1-363 : 89-90

Clathrodrillia colombiana , new species

( Plate 39 )

Type material. Holotype 44.4 x 17.9 mm, J. Poulos! 1991 (UF 470280). No paratypes.

Type locality. Off Cabo de la Vela, Guajira Dept., Colombia, in 200 ft [61 m].

Range and habitat. Colombia (off Guajira Dept.). If the specimens illustrated in Daccarett & Bossio (2011) and K. & L. Sunderland (1999c) are this species, then its range would include Magdalena Dept., Colombia and the Gulf of Venezuela, respectively. The single reported depth is 61 m.

Description. Shell medium (44.4 mm total length; may be to 59 mm, if the Sunderland & Sunderland 1999c report is this species), fusiform with a tall, turreted spire, and narrow, moderately long anterior canal; suture appressed, made somewhat [wavy] over previous whorl’s ribs; whorls straight-sided on spire, number approximately 10 total, the last 58% of total shell length. Sculpture of numerous ribs cut by closely spaced grooves; aperture narrow. Protoconch unknown, missing on holotype. Axial sculpture of numerous narrow ridge-crested ribs (18 on penultimate and 11 on last whorl to varix), straight on spire whorls, slightly sigmoidal on last whorl where they narrow and evanesce on shell base to anterior fasciole. Ribs end abruptly at sulcus, producing squareangled shoulders, extending to suture only as raised lines, or traces not much larger than growth striae. Varix low, broad, hump-like, positioned approximately ⅓-turn from edge of outer lip. Appearing like a series of ribs only partly fused. Spiral sculpture of deep, closely-spaced grooves that result in cord-like spirals overriding ribs. Cords are somewhat ridged (squared rather than round) on their abapical sides, number 5 on penultimate, 15 on last whorl, and 8 more shallow, closely spaced grooves on anterior fasciole. Sulcus flat, wide, with coarse, curved growth striae along with rib traces, and fine spiral grooves that are mostly masked by the ribs and growth striae. Outer lip slightly flattened from varix to its edge such that it protrudes beyond the shell’s circumference; has approximately 10 irregular axial folds; edge forms a low arc from anal sinus to anterior canal with only a slight indentation marking the stromboid notch. Teeth are absent but spiral grooves appear scalloped when viewed ventrally. Anal sinus a deep U-shaped notch offset laterally by the parietal lobe such that it appears spout-like. Inner lip margined, recumbent on parietal wall, erect anteriorly, formed into an elongate lobe on the parietal side of the anal sinus posteriorly. Anterior canal moderately long, open, turned to the right when viewed ventrally, slightly notched; fasciole not swollen. Color yellow-brown overall; aperture, fasciole, and rib crests on shoulder white; brown patch on varix.

Remarks. Taxonomy. Clathrodrillia colombiana has all of the characteristics of Clathrodrillia : strong spiral sculpture, ribs that are angled at whorl shoulders giving it a turreted outline, a hump-like varix, and narrow aperture with a moderately long anterior canal and spout-like anal sinus. Identification. Clathrodrillia colombiana is most similar to C. gibbosa (Born, 1778) and C. petuchi (Tippett, 1995) . It differs from C. gibbosa in being stouter (shorter spire), and broader (W/L = 0.403 versus avge. W/L = 0.371), and in being colored differently. From C. petuchi it differs in having more ribs (18 versus 13–15 on the penultimate whorl), deeper spiral grooves over its shell surface, and in being colored differently.

Although this taxon is based on a single specimen, it is uniquely different from its most similar congeners as explained above. Specimens of C. gibbosa from Colombia do not resemble C. colombiana and thus the latter is not a geographic varient. Furthermore, illustrations in Daccarett & Bossio (2011) and Sunderland &. Sunderland (1999c) are clearly of this species, being similar in appearance, and thus giving evidence that supports the constancy of and validity of this species.

Etymology. The Colombian Clathrodrillia . Named for the country of the type locality.

Figures

PLATE 39. Clathrodrillia colombiana, new species. Figs. 1 – 2: holotype, off Cabo de la Vela, Colombia (UF 470280). Fig. 1: ventral, lateral & dorsal views; Fig. 2: apical view, V = varix; L = edge of outer lip.