CONCHYLW—VITHYRA. 29. 117 



genus: beaks central, pointed and a little curved, with a small 

 impression under them : hinge with two teeth in each valve, one 

 of them cloven. 



29. STmGlLLA—TURTON. 



Testa ovata vel suhglobosa, aquivalvis, clausa, bifariam 

 arcuato-striata. Cardo dentibus subbinis, et laterali in 

 utrdque valvd. Liigamentum externum, ad latus longius 



Shell oval or somewhat globular, equivalve, closed, with striae 

 curving in different directions. Hinge with one or two teeth, 

 and a lateral one in each valve. Ligament external, at the 

 longer side. 



These shells differ from the Tellina, in having tlie ligament 

 placed on the longer side ; from the Lucina in having lateral 

 teeth ; and from both in the remarkable arched striae with which 

 they are furnished, and which we have adopted as a constituent 

 part of their generic character. 



Strigilla testa ovatd iniBquilaterali, striis longiiudmalibiis eainaiia. 



ohliquis hinc flexuoso-angulosis. '' 



Shell oval inequivalve, with oblique longitudinal striae which on 



one side form flexuous angles. 



