HORN EXPEDITION—MOLLUSCA. 
201 
Colotir. —The ground colour is a pale straw, ornamented hy rufous-hi'own 
bands ; two on the spire-whorls, one at the posterior suture and one adjacent to 
the anterior suture ; three on the body-whoi’l, one at the suture, a lu’oader one at 
tlie periphery and a still broader one beneath. 
Sailpture. — Irregular, rounded, growth-ridges following shallow sigmoid 
curv^es on the body-whoid; the whole surface densely covered witli relatively large 
scabrous tubercles; the embryonic whorls are finely granulated in arched rows. 
Dimensions. —Diameters, 15 (excl. lip) and 13-75 ; height, 13 (excl. lip); height 
of last whorl posterior to anterior defiection, 8-75. 
Locality. —Maude River, Hart Range. 
The remarkably dilated continuous peristome of this species is a character 
which separates it from all Australian species, though some approach is made by 
Augase/la cyrtopleura and its allies; moreover the gross granulation is another 
peculiarity. 
Thersites (Badistes .f^) wattii, Tate. (Plate XVIII., Fig. 12.) 
Hadra wattii., Tate, Trans. Roy. Soc. S. Aust., vol. xviii., p. 192, 1894. 
Shell depressedly orbicular, slightly convex above, sides flatly rounded and 
proportionately high, convex below. Whorls seven of very slow increase, convex, 
vei-y narrow, separated by a deeply-impressed suture. Last whorl obtusely angled 
at the j^eriphery, thence flatly convex to the deep narrow suture, the side at first 
nearly perpendicular, then flatly convex to the more regularly and l)roadly convex 
base. Aperture lunate, its posterior angle considerably in advance (vertically) of 
its outer basal margin; slightly descending on the penultimate whorl; peristome 
white-lipped within, reflected, thin and sharp posteriorly, becoming thick and 
obtuse at the base. Umbilicus very small, not at all, or hardly, concealed by the 
reflected columellar margin. 
Colour. —Light brown above, paler beneath. 
Sculpture minutely granulate all over, curved strife of growth on the spire- 
whorls descending to the umbilical mai’gin as deeply sigmoid curves. 
Dimensions. —Diameters, 10-5 and 9-25; height, 5-5; height of last whorl, 4. 
Affijiity. —This species simulates H. leucocheila, Cox, from the unicolorous 
variety of which it differs, particularly, by its very narrow whorls; more whorls 
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