TO GEOLOGY. 173 



F.parva. Plate 6. Fig. 181. 



Description. Shell subfusiform, transversely striate be 

 low, longitudinally and rather widely ribbed, with small 

 spines on the angle of the whorls ; substance of the shell 

 thin ; spire rather elevated ; suture irregularly impressed ; 

 whorls six, angular and subcanaliculate above ; mouth 

 narrow, straight ; columella somewhat oblique, with three 

 folds ; outer lip sharp. 



Length 5-20ths, Breadth 3-20ths, of an inch. 



Observations. This is a smaller species than the last, 

 and may be distinguished by its more tapering spire, its 

 wider ribs and spines, which are, however, small. A 

 single specimen only of this and the last described species 

 having come into my possession, it may be found, in others, 

 that the characters mentioned above are not entirely per 

 manent. 



V. Yanuxemi.* Plate 6. Fig. 182. 



Description. Shell turbinate, transversely striate on the 

 base, with rather large spines above ; substance of the 

 shell thick ; spire short ; suture small ; whorls five, angu 

 lar above ; mouth somewhat narrow ; columella with two 

 folds ; outer lip sharp. 



Length 1.2, Breadth .7, of an inch. 



* I have placed on this species the name of my friend, Professor Van- 

 uxem, one of our most distinguished geologists. 



