Syntomodrillia hypsela (Watson, 1881)

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 : 331

Syntomodrillia hypsela (Watson, 1881)

(Plate 171)

Pleurotoma (Mangelia) hypsela Watson, 1881: 433 : Watson (1886, 341–342, pl. 21, figs. 4a–b).

Not this species, or unconfirmed extralimital reports.

Syntomodrillia hypsela (Watson, 1881) : Rios (2009: 314, sp. 800 [Watson’s fig. 4a]).

Type material. The holotype (by monotypy) 4.8 x 1.7 mm, 10 Sep 1873 (MNHUK 1887.2.9.1058).

Type locality. H.M.S. Challenger! Sta. 122, off Pernambuco state, Brazil, 9.08°S, 34.83°W, in 350 fms [640 m].

Range and habitat. Known only from the holotype.

Description. Watson’s original description was brief because of the poor condition of the shell:

“Shell. —High, narrow, and conical, with very short whorls, of which there are 6; the last whorl exceptionally small, with a short conical base and very small snout; the suture very slight, but extremely oblique; the apex blunt and rounded; there are narrow, high, rounded, curved, and very oblique ribs, which run continuously from the apex to the point of the base, but not to the snout; there are obsolete spiral striae, which become stronger on the point of the pillar. H. 0.19 in. B. 0.067 [4.8 x 1.7 mm]. Penultimate whorl, height 0.033. Mouth, height 0.078, breadth 0.033.

“The specimen of this very marked species is in too bad condition for more minute description. It is very like Pleurotoma (Drillia) exilis, Pease , [= Iredalea exilis (Pease, 1868) from Tahiti] but is much more attenuated, and the last whorl is much shorter.”

Remarks. Taxonomy. Placement in Syntomodrillia is based on the presence of ribs suture-to-suture, a short anterior canal, and faint spirals that are barely discernable in the photograph of the type, the spirals described as “obsolete” by Watson. Dall synonymized this taxon with Splendrillia lissotropis (Dall, 1881) but despite the poor condition of S. hypsela it is considered very unlikely to be a synonym. Watson’s shell is too eroded to give a full description and to make a detailed comparison with S. lissotropis . Identification. Specimens from the general area of the type locality are not available for comparison as possibly the same and a better representative of the species. As such, this species remains enigmatic, the taxon only partially described at this time.

Figures

430289); Fig. 1: ventral, lateral & dorsal views; Fig. 2: apical view, V = varix, L = edge of outer lip; Figs. 3 – 4: paratypes (USNM 430038); Fig. 3: ventral and enlarged view protoconch (not to scale) of incompletely developed specimen; Fig. 4: ventral view of decollate specimen. Figs. 5 – 17: ventral views of additional paratypes and specimens from other localities. Figs. 5, 7 – 11: Grand Cul-de-Sac Marin, Guadeloupe. Fig. 5: MNHN IM- 2012 - 28036; Fig. 7: MNHN IM- 2012 - 28047; Fig. 8: MNHN IM- 2012 - 28045; Fig. 9: MNHN IM- 2012 - 28064; Fig. 10: MNHN IM- 2012 - 28045; Fig. 11: MNHN IM- 2012 - 28046; Fig. 6: Anse Tarare, Guadeloupe (MNHN IM- 2013 - 9092); Fig. 12: off Jamestown, Barbados (USNM 900122); Fig. 13: W of Sandy Lane Bay, St. James, Barbados (UF 470278); Figs. 14 – 15: paratypes, off the N coast of Puerto Rico (USNM 429205 a & USNM 429205); Figs. 16 – 18: Minerva seamount, S Bahia, Brazil (P. Stahlschmidt coll.); Fig. 18: apical view of specimen in Fig. 17, V = varix, L = edge of outer lip.