Dadagulella nictitans (Rowson & Lange, 2007) comb. nov.

Figs 33, 84; Table 1

Gulella nictitans Rowson & Lange, 2007: 27-31, figs 4-7, 14-19.

Type material examined

KENYA: holotype NMK: 1 ad., Taita Hills, Macha Forest Reserve (3.45°S, 38.37°E), leaf litter in indigenous forest (site IB), 1550 m alt., leg. C.N. Lange, 27 Nov. 1998 . Paratypes NMW. Z. 2007.024.00007-00009: 3 ads, data as holotype. Paratype NMW. Z. 2007.024.00010: 1 juv., data as holotype.

Other material examined

None.

Description

SHELL (Fig. 33). Medium-sized (3.60 - 3.90 mm high x 2.00 - 2.20 mm wide), of 5.5 whorls. Ovateacuminate, although spire (spire angle 64 - 69°) less acuminate than in other Dadagulella gen. nov. Apex rounded. Embryonic whorls smoothly granulate. Later whorls with relatively coarse ribs (13 - 15 per mm on penultimate whorl). Sutures of intermediate depth. Umbilicus closed or nearly so. Peristome complete. Outer palatal surface of aperture with a long, furrow-like depression corresponding to the palatal tooth. Dentition 5-fold or 6-fold, consisting of: one V-shaped parietal tooth; one slab-like palatal tooth, forming a conspicuous and narrow parieto-palatal sinus; and two to three shallow columellar teeth, the lower the largest. A deep set-columellar baffle is partly or completely hidden by the constricted aperture, while a basal denticle is completely hidden behind the palatal tooth. However, the baffle and basal denticle are probably present in all specimens. One broken juvenile shell is known; it appears to lack teeth.

CEPHALOPODIUM. Pale cream, with pale tentacle retractors.

SALIVARY GLANDS. United, soft, not tumid, elongate, Y-shaped; each duct leaving at the apex of the lobe and evenly thick throughout.

RADULA. Not successfully prepared.

GENITALIA. Figured in Rowson & Lange (2007).Vas deferens thickened prior to insertion on penis but apparently without diverticulum. Penial sheath absent. Interior of penis with weak radial pilasters, a single longitudinal pilaster, and small rhombic pads. Apical, muscular part of penis with two large hooks, associated with a spatulate “scoop” with microscopically serrated tip. Elsewhere in penis a single longitudinal row of short, simple hooks mounted on rhombic pads.

Range and habitat

Montane forest (1400 - 1900 m) at the type locality and three other Forest Reserves in the Taita Hills, southeastern Kenya (Rowson & Lange 2007).

Remarks

This species is included in Dadagulella gen. nov. on the basis of the apical penial scoop and hooks, and the Y-shaped salivary gland. Its shell features are consistent with inclusion in Dadagulella gen. nov. although the apex is more rounded than in other species. A slightly or strongly rounded apex occurs in D. selene comb. nov. and D. meredithae comb. nov. The parieto-palatal sinus, hidden basal denticle, and columellar dentition of D. nictitans comb. nov. allow it to be separated from other species.