98 Proceedings of the Royal Society of Victoria. 



so regularly convexly rounded, in the absence of the wing-like 

 extension of the outer lip, which is thickened as in V. a/ici/loides, 

 in the much smaller pullus and its more marked centrally exsert 

 tip, and in the presence of line spiral threads, which tend to 

 become obsolete on the body-whorl. Of our other continental 

 species, that to which it is most closely related, and with which it 

 may ultimately prove to be identical, is V. capitafa., Tate, founded 

 upon one specimen said to have come from a well-sinking in the 

 Murray desert. Apart from size, some of the principal points of 

 divergence appear to be the greater number of turns in the pullus 

 and the presence of an extra plait on the columella of V. capiiata. 



35. Voluta spenceri, sp. nov. Plate TV., figs. 1 and 2. 



Shell large, moderately thick, broadly fusiform, with an 

 obtusely rounded mammilate apex, and a few strongly nodose 

 and angular whorls, ending in a long and comparatively narrow 

 aperuure. 



Apical angle about fifty-five degrees. The mammilate embryo 

 consists of about two smooth convex whorls, which ai-e enrolled 

 obliquely, the apex bein^ excentrically inmiersed. Embryonic 

 whorls narrower than the succeeding spire-whorl, and the axis of 

 their enrolment makes an angle of about one hundred 9,nd forty- 

 five degrees with the axis of enrolment of the spire-whorls. 

 Spire consists of five very rapidly increasing strongly nodose- 

 angulose whorls. The angulation of the whorls is situated about 

 the middle of each whorl, becoming slightly nearer the anterior 

 suture anteriorly ; the posterior slope is distinctly concave, as is 

 also the case, but to a much less extent, with the more abrupt 

 anterior slope. The posterior slope becomes less steep and more 

 deeply concave as we proceed towards the body-whorl. Aperture 

 elongate and narrowly oval, very acute and drawn out posteriorly, 

 anterior end unfortunately incomplete in the specimens yet to 

 hand. Outer lip very slightly thickened intei'iially, thickest at 

 the suture, near the outer edge it is gently rounded off from 

 within, and ascends as high as the nodulations cm tlie penultimate 

 whorl, its outer margin being faintly undulatory. Inner lip 

 rather thin, thickest near the posterior of the apeiture, ct)nvexly 

 arched to the columella. Columella slightly twisted and compara- 



