202 
HORN EXPEDITION—IMOLLUSCA. 
(seven in place of five), smaller size and very^ small umbilicus, not at all concealed 
by the columella-reflection. 
The species-name is in compliment to one of my colleagues of the scientific 
staflf of the Expedition who discovered the species. 
Locality .—Maude River, in Hart Range, east of Alice Springs. 
Family BuLiMiDiE. 
Liparus spenceri, Tate. (Plate XVIII., Fig. 13.) 
Reference—Trans. Roy. Soc. S. Aust., vol. xviii., p. 192, 1894. 
Shell oval, spire less than half the length of the .shell; test thin, diaphanous. 
Embryonic whorls two, the tip immersed at the bottom of a shallow crateriform 
summit; the first whorl regularly convex, its posterior margin sharply rounded, 
the second whorl of more rapid increase. Ordinaiy whorls two and a half, convex, 
rather tumid post-medially; suture linear, moderately impressed; last whorl 
moderately inflated. Aperture roundly oval, oblique; peristome simple, straight, 
acute; columellar margin white, expanded and reflected, almost concealing the 
narrow umbilical fissure. 
Colour of a uniform dark horn. 
Sculpture .—That of the apical whorls consists of oblique, slightly raised, 
wavy thi’eads, narrower than the interspaces. That of the ordinary whorls consists 
of oblique, rather crowded, unequal folds of growth and spiral, rather distant 
threadlets; the latter at their junction with the former are elevated into more or 
less elongate pustulations. The last form of ornamentation is most conspicuous on 
the penultimate whorl, becoming fainter with the revolution of the spire, and is 
altogether obsolete on the anterior half of the body-whorl. 
Dimensions. —Length, 20; width, 12'5; diameters of aperture, 11-5 and 8. 
Locality .—Burrowing in loose earth under the shade of fig trees in Glen of 
Palms by the junction with Palm Creek. 
Affinity .—This species is similar in shape to the short and broad variety of 
L. melo, but differs by its thin test, more convex whorls abruptly arched towards 
the posterior suture, and slightly oblique and wider aperture. From all congeners 
it is distinguished by the style of the sculpture of its embryonic whorls. 
