Clathrodrillia marissae, 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 : 101-102

Clathrodrillia marissae , new species

( Plate 44 )

Type material. Holotype 37.1 x 13.7 mm, J. Worsfold! (ANSP 369004).

Type locality. Off Tamarind, Grand Bahama I., Bahama Is., 26°30'45''N, 078°36'00''W, in 183 m. Range and habitat. Known only from the holotype.

Description. Shell medium (to 37.1 mm), fusiform, truncated anteriorly, whorls turreted, number at least 9 (shell apex worn, protoconch missing), convex, last approximately 58% to total length; axial ribs are the predominant sculptural element; anterior canal moderately long. Protoconch is unknown, missing on type specimen. Axial sculpture of narrow, straight ribs, 14 on the penultimate, 8 on last whorl to varix, that run sutureto-suture on spire whorls, evanesce near anterior fasciole of last whorl; narrower than their interspaces; rib crests ridged (not round) and curved in sulcus reflecting outline of anal sinus. Microscopic growth striae dense, visible between spiral cords and in sulcus. Varix hump-like, quite convex; prosocline. Spiral sculpture of evenly spaced grooves forming flat cords that override axials becoming cord-like and nodulose on rib crests, 5 on penultimate, 4 on base posterior to a smooth spiral band without sculpture, then 5 on anterior fasciole. Sulcus wide, concave, with greatly reduced and curved ribs; with microscopic spiral lines but without cords. Outer lip thin, somewhat flattened, with 4 irregular axial folds; exaggerated nodules appear at the intersection of spiral cords and folds. Edge of lip missing so its outline, presence or absence of teeth, and stromboid notch are unknown. Anal sinus a deep Ushaped notch adjacent to suture, edge flared upward. Inner lip moderately wide, recumbent; extending beyond anterior canal anteriorly, thin and recumbent on parietal wall, forming a parietal lobe posteriorly. Anterior canal moderately long, twisted to the right when viewed ventrally; unnotched. Color off-white with an irregular light yellow-brown wash on upper portion of whorls; 3 light to dark brown spiral bands, darkest below shoulder, lightest 2 below suture line and on anterior canal, both visible only on last whorl.

Remarks. Taxonomy. Clathrodrillia marissae has a turreted form, a moderately long anterior canal, ribs from suture-to-suture, a hump-like varix with a dark color patch on leading edge of the varix, and a strong spiral sculpture, which are characteristics of Clathrodrillia . This species is unique among its congeners in possessing nodulose cords. Identification. Clathrodrillia marissae is very similar to C. petuchi (Tippett, 1995) but differs in possessing narrower ribs with wider interspaces, spiral ridges that are more cord-like, and a longer anterior canal. Its shell surface is glossy, not dull, due principally to finer growth striae.

Although this specimen has a fascies similar to several of its congeners ( C. gibbosa , C. petuchi , and C. colombiana ), it possesses characteristics not seen in any of the specimens of these three, namely a very fine, almost polished surface, and axial ribs that are comparatively widely separated (see Plate 50 ). The wide geographic separation of similar congeners (the nearest being C. petuchi reported from as far north as Guadeloupe) is likely an isolating mechanism.

Etymology. Named in honor of Marissa, daughter-in-law and mother of my two grandchildren.

Figures

PLATE 44. Clathrodrillia marissae, new species. Figs. 1 – 2: holotype, Grand Bahama I., Bahama Is. (ANSP 369004). Fig. 1: ventral, lateral & dorsal views; Fig. 2: apical view, V = varix, L = edge of outer lip.

PLATE 50. Clathrodrillia spp. map & lineup. Fig. 1. Map of approximate known localities. Figs. 2 – 7: 10 mm scale bar. Fig. 2. Holotype, 31.0 x 11.3 mm, C. rubrofasciata, new species (MZSP 122061). Fig. 3. Holotype, 27.0 x 9.6 mm, C. garciai, new species (MNHN IM- 2013 - 55984). Fig. 4. Holotype, 16.6 x 6.0 mm, C. wolfei (Tippett, 1995) (USNM 880070). Fig. 5. Holotype, 14.7 x 5.8 mm, C. guadeloupensis, new species (MNHN IM- 2013 - 7812). Fig. 6. Lectotype, 12.6 x 4.7 mm, C. tryoni (Dall, 1889) (USNM 87449). Fig. 7. Holotype, 10.5 x 4.0 mm, C. parva, new species (USNM 1291333). Figs. 8 – 12: 20 mm scale bar: Fig. 8. Non-type, 48.9 x 17.3 mm C. gibbosa (Born, 1778) (author’s coll.). Fig. 9. Holotype, 44.4 x 17.9 mm, C. colombiana, new species (UF 470280). Fig. 10. Holotype, 39.2 x 15.8 mm, C. petuchi (Tippett, 1995) (USNM 880071). Fig. 11. Holotype, 37.1 x 13.7 mm, C. marissae, new species (ANSP 369004). Fig. 12. Non-type, 32.2 x 12.3 mm, C. dautzenbergi (Tippett, 1995) (author’s coll.).