BOUCHET, Fedosov & Puillandre & Herrmann & Kantor & Oliverio & Dgebuadze & Modica & Bouchet, 2018

KANTOR & BOUCHET GEN. NOV.

( FIGS 17G, H, 18A–H)

Type species: Profundimitra taylori sp. nov.; OD, herein.

Diagnosis: Small shell (20–35 mm), thin walled, fusiform or elongate-fusiform, with high orthoconoid or slightly acuminate spire. Protoconch pale, semi-translucent, narrowly conical with three or more smooth whorls (usually strongly eroded). Suture adpressed, sometimes shallowly canaliculated. Teleoconch whorls gently convex, early teleoconch whorls sometimes subcylindrical. Sculpture variable, from very weak, represented by indistinct spirally aligned punctures, to deep spiral grooves separating flat, rounded or distinctly gemmate spiral cords. Siphonal canal rather long, straight, tapering, not notched at its tip. Aperture elongate. Outer lip very thin, convex, smooth or slightly undulating. Inner lip with three columellar folds, usually fine but well pronounced, sometimes very weak. Shell white, pale to yellowish, sometimes covered by light brown periostracum. Radula with laterals and rachidian of equal width, with evenly convex anterior margin bearing 12–14 equal pointed cusps ( Fig. 17G, H).

Distribution: Indo-Pacific, bathyal depths, mostly on mud.

Species included: Profundimitra abyssicola ( Schepman, 1911) 3 comb. nov., Profundimitra planofilum ( Huang, 2011) 1 comb. nov., P. taylori sp. nov. 1.

Etymology: The name Profundimitra refers to the fact that all known species of this new genus inhabit deep water. Gender feminine.

Remarks: Whereas all the sequenced species of Calcimitra were identifiable to known species, the new deep-water genus Profundimitra (as well as the related Fusidomiporta ) appears to represent a kind of Mitridae terra incognita. Of four species recognized in our phylogenetic analysis, only P. planofilum has a name. The latter was initially described in Cancilla , and indeed the sculpture pattern and light brown marks on spiral cords of P. planofilum strikingly resemble the pattern seen in species of Cancilla . Profundimitra planofilum , however, differs from Cancilla by the shell base outline, which is distinctly concave, and by a slightly higher spire. The immature lectotype of C. abyssicola figured by Cernohorsky (1991) is very close to species of the Profundimitra clade in shell characteristics, and we tentatively assign this species to Profundimitra . It should be noted, though, that C. abyssicola as circumscribed by Cernohorsky combined a variety of forms, some of them [like the specimen figured by Cernohorsky (1970: pl. 6, fig. 7), which is undoubtedly conspecific with our specimens IM-2007-35711 and IM-2007-35618] referable to Profundimitra gen. nov., but most likely not conspecific with the lectotype, while others obviously represent true Cancilla or Imbricaria as circumscribed here.

The genus Profundimitra gen. nov. can be recognized by the elongate, typically weakly sculptured shell, either white or pale, sometimes covered with light brown periostracum. The genus Calcimitra is closest to Profundimitra gen. nov. in shell morphology; however, species in the latter genus have proportionally higher spire and, correspondingly, lower last adult whorl and siphonal canal. Another genus which seems superficially close to Profundimitra gen. nov. is Eumitra , which however is characterized by a smooth columella, typically with no folds or with only one or two distinct folds, while species of Profundimitra gen. nov. have three or more columellar folds, albeit sometimes slightly sunken in the aperture. Another notable difference between the two genera is the morphology of protoconch: it is narrow and narrowly conical in Profundimitra , very distinctly demarcated from the much wider first teleoconch whorl, whereas the protoconch of Eumitra is very low, cyrtoconoid, and not clearly delimited from teleoconch. Moreover, Profundimitra gen. nov. has a characteristic radula morphology with rachidian and laterals of equal width and similar morphology, as opposed to the very small, narrow rachidian and wide laterals of Eumitra .

GENUS FUSIDOMIPORTA FEDOSOV, HERRMANN ,