20 



Shell some'n'hat angular, compressed dorso-ventrally, with lateral 

 keels. An anterior transverse section is thus always angular 

 laterally, A crest or rib generally extends longitudinally along 

 the back, and usually projects. The embryonic shell is variable 

 in form, but may always be distinctly separated. 



Type. — Clio pyramidata, Linn. 



Subgenus STYLIOLA, Lesueur. 

 \Ih Blainville, Manuel de Malacologie, 1825, p. 655.] 



Shell conical, straight, elongated ; surface smooth or faintly 

 striated ; dorsal groove not parallel to axis of shell, but slightly 

 oblique, with only the anterior extremity (which ends in a rostrum) 

 in the median line ; embryonic portion ends in a pointed apex. 



Type. — Styliola recta, Lesueur (MS.) = Cleodora suhula, Quoy 

 and Gaimard. 



Clio (Styliola) rangiana, Tate (sp.). 



1887. Styliola rangiana, Tate, Trans. Eoy. Soc. South Aust. vol. ix. 



p. 194, pi. XX. fig. 2. 

 18S9. Styliola rangiana, Dennant, id. vol. xi. p. 48. 



Its rounded sides and dorsal groove serve to distinguish this 

 species from C. licarinata, Tate, found in the same beds. Near 

 the summit of the shell is a conspicuous inflation, whilst the 

 apex is much swollen and abruptly tapers to a fine point. Pro- 

 fessor Tate's figure barely does justice to this structure, and it 

 is interesting enough to demand another figure, which is now 

 given (Plate I. Figs. 6«-5) as seen under a microscope with a 

 one-inch objective. 



The phenomena in the neighbourhood of the apex recall the 

 genus JEucMlotheca, Fischer, to some extent, but many fundamental 

 differences exist. In particular, C. rangiana has no reversed or 

 collareted border round the aperture ; whilst its pronounced 

 longitudinal sulcus, extending from the aperture almost to the 

 apex, is very distinctive. The whole shell is somewhat compressed 

 dorso-ventrally, and its almost smooth and polished surface is 

 ornamented with oblique transverse striations. 



Professor Tate remarks that, compared with shells of the living 



