CONCHOLOGY. 49 



P. cserulescens. P. aurantia. 



P. elongata. P. fragilis. 



P. flavicans. P. livida. 



P. sqamosa. P. galathea. 

 P. pulchella. 



P. lusoria.* P. Pacifica.* 



P. fusca.* P. Florida * 



3. Genus Psammotxa. PI. VII. 



Jnimal. Unknown. 



Shell. Of the same form as the Psammobia, but diflfering in 

 the number of teeth, the left valve of the Psammotaea having only 

 one tooth; and sometimes one valve is without teeth, while the 

 other has two ; ligament exterior, attached to callosities at the 

 hinge, and without an irregular plait. Inhabits the Australian 

 seas. Seven species. One fossil species. 



Psammotaea violacea. Psammotaea Candida. 



P. zonalis. P. tarentina. 



P. pellucida. P. donacina. 



P. serotina. 



N. Telliijaria. Seven Genera. 

 The two last of these genera have no lateral teeth, the rest have 

 one or two. 



4. Genus Telina. PI. VII. 



Animal. Body triangular, much compressed : the free edge of 

 the mantle furnished with a row of tentacular, largest and longest 

 in the rear; foot very large, compressed and pointed to the front; 

 buccal appendages nearly as large as the bronchial laminae, of 

 which the external pair are much smaller than the internal ; the 

 anterior contractile muscle larger than the other ; tubes very dis- 

 tinct. 



Shell. Of a somewhat variable form, generally striated longi- 

 tudinally and much compressed, equivalved, more or less inequi- 

 lateral ; the anterior side almost always longer and more rounded 

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