Dadagulella nictitans ( Rowson & Lange, 2007 ) Rowson & Tattersfield, 2013

Rowson, Ben & Tattersfield, Peter, 2013, Revision of Dadagulella gen. nov., the “ Gulella radius group ” (Gastropoda: Streptaxidae) of the eastern Afrotropics, including six new species and three new subspecies, European Journal of Taxonomy 37, pp. 1-46 : 22-23

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Dadagulella nictitans ( Rowson & Lange, 2007 )

comb. nov.

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

Figs 33 View Figs 27-35 , 84 View Fig ; Table 1 View 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 GoogleMaps . 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



SHELL ( Fig. 33 View Figs 27-35 ). 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).


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.


National Museums of Kenya


Naturhistorisches Museum, Wien


Universität Zürich


Harvard University - Arnold Arboretum














Dadagulella nictitans ( Rowson & Lange, 2007 )

Rowson, Ben & Tattersfield, Peter 2013

Gulella nictitans

Rowson B. & Lange C. N. 2007: 31