Fenimorea crocea, 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 : 157-158

Fenimorea crocea , new species

( Plate 73 )

Type material. Holotype 15.6 x 6.0 mm, D. Steger! (UF 155640).

Type locality. 225 km ENE of Alacran Reef, 190 km N of El Cuyo, Campeche Bank, off Yucatan State, Mexico, in 119 m.

Range and habitat. Known only from the holotype.

Description. Shell small (15.6 mm total length), fusiform with a tall spire, truncated anteriorly; of approximately 8¾ convex whorls that become more so anteriorly, last about 59% of total shell length. Surface glossy, bold ribs the dominant sculptural element; aperture narrow. Protoconch approximately 2 whorls, eroded on holotype. Axial sculpture of low slightly opisthocline broad round-crested ribs that stretch from suture-to-suture on spire whorls, evanesce on shell base near anterior fasciole. Ribs tend to line up on early whorls, highest mid-whorl, are most angular on last; slightly narrower than their interspaces; number 9 on penultimate, 6 on last whorl to varix. Varix narrow, about ⅓-turn from the edge of the outer lip. Spiral sculpture of incised, regularly spaced grooves or threads made jagged by the intersection of fine, more closely spaced growth striae, creating rows of pits characteristic of Fenimorea . Sulcus concave, demarcated by the abrupt decrease in height of the ribs; ribs curved, low; spiral sculpture faint but present, masked by heavier curved growth striae. Outer lip thin, slightly flattened from varix, with 5 folds; edge smooth, not scalloped, bent inward. Edge of lip forms a low almost flat arc from and congruent with the anterior edge of the anal sinus to the stromboid notch, which is shallow. Anal sinus on shoulder close to suture, deep, U-shaped, entrance not constricted, or only slightly so. Inner lip narrow, thin, margined, slightly elevated anteriorly along canal, thinnest and recumbent on parietal wall, formed into a parietal lobe posteriorly at junction with outer lip. Anterior canal is moderately long, well defined, open, end turned slightly to the right when viewed ventrally, notched at its tip; anterior fasciole not swollen. Color base is saffron; intercostal spaces and band overriding ribs below periphery are golden brown.

Remarks. Taxonomy. Fenimorea crocea has the principal characteristics of the genus: typical microsculpture, ribs that extend from suture-to-suture with a well-demarcated sulcus, and a deep U-shaped notch anal sinus. The varix is not hump-like, and the canal is moderately long, typical features of offshore, deep water species. Identification. Fenimorea crocea is similar to F. c o nt r a ct a, new species, F. t i p pe t t i, new species, F. petiti Tippett, 1995 , and F. chaaci (Espinosa & Rolán, 1995) . Its golden brown color offset with saffron ribs is similar to the color pattern of F. contracta but that species has fewer, more widely spaced ribs. From F. t ippet ti it differs in being smaller, stockier, and possessing a golden brown band, not a reddish brown one. The color pattern is also different. From F. petiti it differs in possessing a more distinct, wider sulcus, more angular whorls, spiral grooves, and a wider, more diffuse mid-whorl color band. From F. chaaci it differs in being smaller but with relatively larger and fewer ribs, a longer anterior canal, and a narrow, not hump-like varix. Fenimorea crocea has features characteristic of deep water species while C. chaaci those of shallow water.

While this taxon is based on a single specimen, it exhibits important characteristics that separate it from its closest congeners as explained above. These differences are also not seen in any of their varients and so the specimen is believed to merit description as a separate species.

Etymology. The Saffron-colored Fenimorea ; named for the shell’s base color. From the Latin adjective croceus, feminine crocea , meaning saffron-colored.

Figures

PLATE 73. Fenimorea crocea, new species. Figs. 1 – 3: holotype, ENE of Alacran Reef, Mexico (UF 155640). Fig. 1: ventral, lateral & dorsal views; Fig. 2: enlarged view of protoconch (not to scale); Fig. 3: apical view, V = varix, L = edge of outer lip.