190 
HORN EXPEDITION—MOLLUSCA. 
more flatly convex base. Aperture oval (nearly circular), almost parallel with the 
base of the shell ; the plane of the aperture very oblique to the vertical axis of the 
whorl; margins united and reflected all round; peristome bordered by a broad 
and deep constriction extending from the umbilical edge to the suture; umbilicus 
wide and deep, two and three-fourths the diameter of the base. 
Colour. —Uniformly light brown, beneath a thin periostracum which is 
raised into short, somewhat distant, bristles coincident with arched growth-lines 
on the test beneath. 
Sculpture. —The one-and-a-half apical whorls are minutely granulated. 
Beneath the periostracum the test is raised into very slender, crowded, raised 
lines, abruptly bent back, and surmounted here and there by granule-like bosses 
on which the bristles arise. The growth-lines extend on the body-whorl from the 
suture into the umbilical concavity. 
Dimensions. —Diameters, 13‘5 (inch lip) and 11; height, 6; height of last 
whorl behind peristomial deflection, 5 ; diameters of aperture, 7 and 6‘5. 
Localities. —Rev. H. Kempe (one bleached example) ; McDonnell Range, J. 
East (one fresh specimen). This species proved to be rather widely distributed, and 
individually very abundant. It extends from the Krichaufl' Range (as in Glen of 
Palms and Palm Creek) to the Finke Gorge and to the glens about Mount Sonder 
and Brinkley Bluff, and as far north as Painta Spring on the north margin of the 
foot hills of the McDonnell Range bordering Burt Plain. 
AJfinity. —This species is similar to the depressed forms of A. cyrtopleura., Pfr., 
but apart from its bristly periostracum it difters by gi’owth-lines, very much more 
slender and numerous, umbilicus wider, and by the presence of a deep constriction 
behind the aperture. The species-name, setai-bearing, has reference to the bristles 
on the periostracum; it is, however, occupied in the genera Helicigona {Helix 
setigera, Zygl.) and Nanina {Helix setigera, Gow), and if there is valid objection 
to its employment in the epiphallogonous Helicidie, I propose the name larapinta 
in substitution. 
Angasella euzyga, Tate. (Plate XVII., Fig. 7.) 
Reference— Hadra euzyga., Tate, Trans. Roy. Soc. S. Aust., vol. xviii., 
p. 194, 1894. 
Shell planorbiform, spire flat or hardly perceptibly raised. Whorls four, of 
rather slow increase, flatly convex, separated by a deeply-impressed suture ; apical 
