CTPEiEA. 209 



G. 4304. Example of a fully-grown individual. 



Presented by John Dennant, Esq. 



Csrprsea (Erosaria) platypyga, M'Coy. 



1876. Cyprtea [Aricia) platijpyga, M'Coy, Prod. Pal. Viet. dec. iii. pi. xxx. 



figs. 1-1 c. 

 1890. Cyprma platypyga, Tate, Trans. Roy. Soc. South Aust. vol. xiii. 



pt. 2, p. 211. 

 1893. Cyprcea platypyga, Tate and Dennant, id. vol. xvii. pt. 1, p. 221. 

 1896. Cyprcea platypyga, Pritchard, Proc. Eoy. Soc. Vict. vol. viii. n.s. 



p. 106. 



This large species is characterized by its solidity, the narrowness 

 of the aperture, grooved and ridged on either side, the grooves on 

 the columellar border extending well over the surface outwardly. 

 The shell is globose, smooth, furnished with solid, broad, flattened 

 extensions posteriorly, through which the short posterior canal 

 is cut ; anterior canal sharply bent towards the dorsal surface, 

 and flanged by thick, flattened callosities. 



The short, very wide, truncate posterior extension, and the 

 prolongation posteriorly of the inner margin of the aperture, 

 which rises above the level of the callosity on the opposite side, 

 are distinctive. The enormous grooves on the columellar border 

 are not characteristic of Erosaria, in which it is here placed, but 

 in other respects it recalls that subgenus. 



Dimensions. — Length 79 mm. ; breadth 46 mm. 



Form, and Loc. — Eocene : Victoria. 



70405. Example of the adult ; from Mount Martha. Purchased. 

 G. 4305. An example of the adult, having the inner border 

 much prolonged anteriorly ; from Muddy Creek. 



Presented by John Dennant, Esq. 



G. 5477. Specimen in which the anterior canal is bent almost 

 at a right angle with reference to the axis of the shell ; from 

 Muddy Creek. Purchased. 



Subgenus UMBILIA, Jousseaume. 



[Bull. Soc. Zool. France, t. ix. 1884, p. 90.] 



Shell depressed anteriorly; spire umbilicated; extremities pro- 

 duced and beaked; aperture sinuous, ridged on either side, or, 



p 



