Small snails in a big place: a radiation in the semi-arid rangelands in northern Australia (Eupulmonata, Camaenidae, Nanotrachia gen. nov.) Köhler, Frank Criscione, Francesco Zoological Journal of the Linnean Society 2013 Zool. J. Linn. Soc. 2013-08-29 169 1 103 123 [914,1254,950,971] Gastropoda Camaenidae Nanotrachia Animalia Stylommatophora 16 119 Mollusca species undetermined    Holotype   Australia, WA, EK, 40.6 kmnorth-west of  Nicholson StationHomestead, limestone area with numerous gullies, base of cliffs,  Spinifex, and talus, under rocks in loose soil, 17°49′30″S, 128°34′40″E(coll. V. Kessner,  1 September 2009); dissected specimen ( WAM S66300).   Paratypes  Same data as holotype; two wet ( WAM S49178), 85 dry ( WAM S49100).  Etymology In reference to the peripheral keel of the shell, derived from ‘carinatus’ (Latin = possessing a keel), adjective of feminine gender.  Description  Shell ( Figs 4B, 5A, B):Average in size; periphery shouldered, strongly keeled; 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 with weak, blunt, narrowly spaced axial ribs, interrupted on keel; apertural lip reflected, moderately expanded; yellowish–horn.  Genitalia ( Fig. 6C):Epiphallus very short, onequarter of penial length; no muscle fibres connect the epiphallus and penial apex. Vas deferens entering penial sheath almost halfway up. Penial wall thin, with two longitudinal pilasters, one wide, irregular, comprising half of penial wall, second pilaster thinner, irregularly shaped, winding, with regularly spaced, pointed corrugations; penial pore surrounded by subcircular ridge. Vagina slightly shorter than penis, half to twice as long as free oviduct.  Comparative remarks Shell similar to  N. coronata sp. nov., but smaller in size, axial ribs interrupted on keel. Differs from  N. levis sp. nov.by presence of keel, from all other congeners by less developed axial ribs. The largest shells of  N. carinata sp. nov.are similar to the smallest shells of  O. elegans, which differ by more elevated spire and weaker developed periostracal projections. Genitalia identical to  N. coronata sp. nov.,  N. levis sp. nov.has three pilasters, and all other species have smooth pilasters. S66300 2009-09-01 WA, EK, WAM V. Kessner Australia -17.825 Nicholson Station Homestead 21 128.57777 Nicholson Station 16 119 1 holotype S49178, S49100 2009-09-01 WAM V. Kessner Australia -17.825 Nicholson Station Homestead 21 128.57777 Nicholson Station 16 119 1 paratype