PURPURINA. 93 



P. inflata is characteristic of the ParJcinsoni-zone of Burton Braclstock and the 

 neighbourhood. The Saazei-bed at Oborne also yields it, and specimens resembling 

 this species are in Mr. Buckman's collection, said to come from East Coker, zone 

 unknown. It also occurs at Dundry, and in the Inferior Oolite of Rodborough 

 Hill, and Cold Comfort. 



In Normandy it is fairly abundant in the " Oolithe ferrugineuse," whence many 

 fine specimens are to be seen in Prof. Deslongchamps' collection. 



11. Purpurina : Cf. Sowerbyi, Waagen, 1867. Not figured. 



1867. Purpurina Sowerbyi, Waagen. Zone of Am. Soiverlyi, in Benecke, p. 105, 



pi. v, figs. 3, 4<a, b,c. 



A globose Purpurina which differs from P. inflata, in having the shoulder of 

 the whorl sloping, and scarcely canaliculate, is of rare occurrence in the Sowerbyi- 

 bed of Bradford Abbas. The spire also is rather shorter, and the costas have a more 

 decided inclination from left to right. 



12. Porpurina rotunda, sp. nov. Plate II, figs. 3fl,&,c;3 d. 



Description : 



Length of well-grown shell . . .23 mm. 



Ratio of width to length . . . 82 : 100. 



Length of body-whorl to entire shell . . 68:100. 



Spiral angle .... 90°. 



Shell ovate-globose, rather widely umbilicated. Whorls five to six, tumid and 

 canaliculate near the suture ; body-whorl much inflated. The costse are feebly 

 developed on the whorls of the spire, and more or less effaced on the body-whorl. 

 The spirals are numerous and regular in their increase and relative distance. 

 Aperture widely ovate, with but slight traces of canaliculation. 

 Relations and Distribution. — Though not more tumid than P. inflata this is the 

 most globose of all the Purpurines. It is further distinguished by a good sized, 

 circular umbilicus. The aperture is, perhaps, the least canaliculate of any known 

 species. 



Rare in the Sowerbyi-hed of Bradford Abbas and Stoford. 



