Kermia clathurelloides, Kilburn, 2009

Kilburn, Richard Neil, 2009, Genus Kermia (Mollusca: Gastropoda: Conoidea: Conidae: Raphitominae) in South African waters, with observations on the identities of related extralimital species, African Invertebrates 50 (2), pp. 217-217 : 221-223

Kermia clathurelloides sp. n.

Figs 5–7

Etymology: From the genus name Clathurella Carpenter, 1857 ; it refers to the teleoconch being superficially similar to some species of latter genus.

Description: Shell fusiform with truncated base; b/l 0.35–0.38, a/l 0.38–0.41; whorls strongly convex with narrow angular shoulder, and undulant, fairly deep suture, base of last whorl without a waist-like constriction; rostrum narrow, without a fasciole; aperture narrowly elliptical; siphonal canal strongly contracted but slightly expanded terminally, end truncate, oblique in dorsal view, not notched. Outer lip evenly convex in side view, not serrated, anal sinus moderately deep, linguiform, its opening constricted, margin raised; inner edge of lip with 9–11 weak, ridge-like teeth, one at each end stronger than others, but in some specimens very irregular; inner lip smooth, shallowly sinuous, thinly calloused, parietal pad weak.

Sculpture cancellate, with spiral ridges finer than axial ribs, forming weak compressed nodules where they cross them.Axial ribs slightly opisthocline, almost straight, weakly sigmoid on last whorl, terminating (or weakening) above, slightly short of suture, on base extending to top of rostrum; on last whorl continuing to outer lip; in t/s constricted, steep-sided, sharply rounded, equal to or slightly narrower than their flattened intervals, 10 or 11 on 1 st teleoconch whorl (first few ribs weak), 15 or 16 on penultimate whorl. Spiral ridges narrower than their intervals, nearly equal in strength, except for those on base of last whorl which are uneven; 1 st whorl with 3 spiral ridges, the upper two close together; penultimate whorl with 8–12 ridges, base with 6–8, plus 4–7 smooth, slightly angular ridges on rostrum (which may become obsolete distally). Interstices with fine, close axial striae.

Protoconch ( Fig. 7 ) bluntly conical, of ca 3.0 whorls, beginning of 1 st whorl strongly tilted, next whorl finely cancellate, last whorls with obliquely cancellate sculpture, of sigmoid, opisthocyrt riblets, crossed diagonally by oblique threads; golden brown; breadth 0.41 mm.

Slightly glossy, medium or golden brown, with obscure darker and lighter bands, spiral ridges more or less darker than intervals, last whorl with a terminal brown band basally; interior of outer lip white, protoconch orange-brown.

Dimensions: 11.3×4.0 mm (holotype); 12.0× 4.3 mm (paratype).

Comparison and remarks: Within the genus Kermia , the new species shows some resemblance to K. producta ( Pease, 1860) , but that species is only about half the size of K. clathurelloides (adults of both species having a maximum of about six teleoconch whorls), axial ribs are much finer in producta (20–22 on the penultimate whorl against 15 or 16) and markedly straighter, and the suture is crenulated by the rib terminations in clathurelloides , but not in producta . There also appears to be some resemblance to K. thorssoni Chang, 2001 , from Taiwan (types not seen), but K. clathurelloides differs in its later whorls being distinctly shouldered, the last whorl lacking a submedian angle and the spiral ridges are much finer (in thorssoni these are subequal in strength to the axial ribs and fewer on the penultimate whorl (five according to Chang), whereas these number 8–12 in K. clathurelloides ).

A relationship with Clathurella exilis Pease, 1860 , from Hawaii is also possible. Unfortunately, the lectotype of that (BMNH 1962766, designated by Kay (1965: 21, pl. 2, figs 17, 18)) lacks its protoconch. Kay (1979: 356, fig. 116J) referred exilis to the genus Paramontana (a probable clathurelline group with smooth protoconch), but her illustration appears to show finer sculpture and a more elliptical aperture than the lectotype ( Figs 8, 9 ), so that confirmation of the identity of her material is needed. Compared with the lectotype of exilis , K. clathurelloides has weaker lip denticles, a distinct shoulder angle to the ribs, and a much more constricted base.

K. clathurelloides shows a superficial resemblance to several species generally referred to the genus Lienardia Jousseaume, 1884 . Of these, the most similar species (apart from colouration) appear to be L. roseotincta (Montrouzier in Souverbie & Montrouzier, 1872), which also occurs in KZN, and L. montrouzieri (Souverbie, 1860) . However, these two species are typical Lienardia in possessing a keeled protoconch, whereas that of K. clathurelloides not only lacks a keel but has the typical diagonally cancellate sculpture of Kermia .

Holotype: NMSA W6533 /T2360. SOUTH AFRICA: KwaZulu-Natal: off Reunion Rocks, Durban (29°58'S: 30°56'E), ca - 130 m, sand and rubble bottom, dredged G. Smith.

Paratype 1: same data as holotype, to be deposited in BMNH . Paratype 2: KwaZulu-Natal: Leadsman Shoal , - 24–26 m, stone washings (D. Herbert; NMSA E2634 /T2343) . Eastern Cape: Off Port Grosvenor , - 80 m, calcareous nodules (R. Kilburn et al.; NMSA C7367 /T2342) .

Other material examined comes from the type locality and is in G. Smith’s collection.

Distribution: Eastern South Africa, from northern KZN to Eastern Cape, inner continental shelf.

Figures

Figs 1–7. Kermia geraldsmithi sp. n., Pseudodaphnella (?) excellens (Sowerby, 1913), and Kermia clathurelloides sp. n.: (1–3) K. geraldsmithi, holotype NMSA W6533/T2354, 4.6×2.1 mm, apertural (1) and side (2) views, and ESEM of protoconch (3); (4) Pseudodaphnella (?) excellens, holotype of Clathurella excellens, BMNH 1914.1.7.267, Osumi, Japan; 9.6×4.2 mm; (5–7) K. clathurelloides, holotype NMSA W6533/T2360, 11.3×4.0 mm, apertural (5) and side (6) views, and ESEM of protoconch (7).

Figs 8, 9. Clathurella exilis Pease, 1860, apertural and side views, lectotype BMNH 1962766, Sandwich Is., Hawaii, 5.7×2.1 mm.