CJRONIA. 179 



Subgenus Cronia, H. &, A. Ad. 



P. AMYGDALA, Kiener. PI. 55, fig. 174. 



Orange or cream-color ; the principal revolving ribs lighter 

 in tint; frequently Jbrown-tinged at base; cream-color within the 



aperture. Length, 1 1*4 inches. 



Australia. 



This species is, in its typical state, thickly covered over its 

 entire surface with small, arched scales, covering its close ribs; 

 I am much inclined to think, however, that P. au.'ra nliara is 

 merely a smooth state of the same species. 



'P. AIKANTIACA, ilnmbr. PI. 55, tig. 175. 



Orange-colored, more or less tinted with brown; sometimes 

 white-banded. Length, 35 mill. M of Hogo i eUt 



Probabl a smooth var. of P. (i 



P. BurciNKA, Desh. PI. 55, fig. 17(5. 



Brown ; larger revolving ribs articulated with white and 

 darker brown ; aperture cream-colored to light brown. 



Length, 1'25-1'75 inches. 



New Guinea. 



The distinguishing characteristic of this species is an obtuse 

 angle or protrnberance upon the very centre of the columella ; 

 this might put it along with P. coin nu'llaris in Mr. Ball's sub- 

 genus Purpui'fJlft : but the angle is not persistent in some of the 

 fully grown specimens. Except the angle and the narrower form 

 of the shell, this species closely approximates to vars. of P. 

 imujydnla. Kiister adopts the name flartlmea as of Chemnit/, 

 but this author was not binomial, and the identification of the 

 species is surely an error. 



P. OASTANEA. Krauss. PI. 55, fig. 177. 



Chestnut-brown ; purple within. Length, '6 inch. 



Cape of Good Hope. 

 \ young shell which perhaps belongs to this group. 



P. ALBA, Hombr. and Jacq. PI. 55, fig. 178. 



White, externally and internally. Length, 1 inch. 



Isle of Manganeva. 



This is also a young shell, the generic position of which is 

 verv doubtful. 



