ODOSTOMIA. 277 



flattened below it, but gradually attenuates, with a gently 

 rounded declination, at the somewhat produced base. There 

 is a sHght umbilical chink, but not a decided perforation. 

 The mouth, which is rather large, and more or less elon- 

 gated, has an oval-acute figure, being rounded below, and 

 gradually contracted above ; it usually occupies from two- 

 fifths to three-sevenths of the entire ventral length. The 

 outer lip, which is quite smooth internally, is convex above, 

 and well arcuated below. The j^illar lip, which forms one 

 continuous curve with the inner lip, is elongated, straightish, 

 scarcely at all reflected, and not appressed ; it is furnished 

 with a small and retired, yet tolerably distinct, fold, that 

 is seated rather above the middle of the aperture. Very 

 few examples exceed the eighth of an inch in length. 



The ascertained localities are only the following — South- 

 ampton, Torquay, Exmouth, west coast of Scotland, 

 Lerwick (Jeff. Ann. Nat.). 



The species approaches more closely than we could wish 

 to the preceding, of which, perchance (for much latitude 

 of form seems permitted to the Odostomice), it may after all 

 prove an aberrant variety. Yet, when mixed with that 

 species, the eye will almost invariably detect it at a glance, 

 by its much shorter and not eftuse mouth, the greater 

 curvature and lesser reflection of the pillar lip, its umbilical 

 chink, &c. 



