Nanotrachia undetermined

Köhler, Frank & Criscione, Francesco, 2013, Small snails in a big place: a radiation in the semi-arid rangelands in northern Australia (Eupulmonata, Camaenidae, Nanotrachia gen. nov.), Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 169 (1), pp. 103-123 : 121

NANOTRACHIA LEVIS SP. NOV.

Holotype

Australia, WA, EK, 6.7 km south-west of Lissadell Station Homestead , narrow limestone ridge, base of cliffs, small pockets of vine thicket, under rocks in loose soil, 16°43′17″S, 128°30′46″E (coll. V. Kessner, K. Carnes, 6 September 2009); dissected specimen ( WAM S66303 ).

Paratypes

Same as holotype; 67 wet ( WAM S49199 ), 109 dry ( WAM S49096 ) .

Other material: Table 1.

Etymology

In reference to the smooth shell surface and lack of axial sculpture, derived from ‘levis’ (Latin = smooth); adjective of feminine gender.

Description

Shell ( Figs 4E , 5G, H ): Average in size, periphery rounded, without keel; spire weakly elevated; umbilicus open, wide, not concealed by columellar reflection; protoconch and teleoconch with dense, pointed periostracal projections and fine axial growth lines; teleoconch without ribs; apertural lip reflected, moderately expanded; horn to light brown.

Genitalia ( Fig. 6D ): Epiphallus very short, one fifth of penial length; no muscle fibres connecting epiphallus with penis apex. Inner penial wall with two longitudinal pilasters, one thick, tapering in width towards base, with weak projection, not reaching proximal end of wall, second pilaster thinner, with pointed corrugations, extending entire length of wall. Vagina half as long as penis, as long as free oviduct.

Comparative remarks

Shell differing from other congeners by absence of axial sculpture. Genitalia similar to N. carinata sp. nov. and N. coronata sp. nov., but differing by shape and size of pilasters (one being narrower and longer, the other being straight); differing from all other congeners by presence of pointed corrugations.

Figures

Figure 4. Shells of Nanotrachia species studied herein. A, N. intermedia (Solem, 1984) (paratype AM C.146110); B, Nanotrachia carinata sp. nov. (paratype WAM S49100); C, N. coronata sp. nov. (paratype WAM S49086); D, N. costulata costulata sp. nov. (WAM S49088); E, N. levis sp. nov. (paratype WAM S49096); F, N. orientalis (Solem, 1984) (paratype AM C.146105); G, Mouldingia occidentalis (Solem, 1984) (paratype AM C.146107). Scale bar = 1 cm.

Figure 5. SEM micrographs of shells showing protoconch and teleoconch microsculpture. A–B, N. carinata sp. nov. (paratype WAM S49100); C–D, N. coronata sp. nov. (paratype WAM S49086); E–F, Nanotrachia costulata sp. nov. (WAM S49088); G–H, N. levis sp. nov. (paratype WAM S49096). Scale bars: A, C, E, G = 1 mm; B, D, F, H = 200 Mm.

Figure 6. Penial anatomy. A, Nanotrachia intermedia (Solem, 1984) (WAM S49195); B, N. intermedia (Solem, 1984) (WAM S49194); C, Nanotrachia carinata sp. nov. (holotype WAM S66300); D, N. levis sp. nov. (holotype WAM S6630). Insets showing schematic cross section of mid-penis. Scale bar = 2 mm.