100 Mr. S. Stutchbury on ttco new genera of MoUusca. 



to the cardinal pits : a nearly obsolete depressed line obliquely crossing 

 the internal disk of each valve, from the umbones to the inferior margin. 



Anatina crassa. 

 Tab. Supp. xliii. f. 5, 6. 



^. testa crassa, sublrigond, inaquivalvi, transversim costatd ; valvd 



sinistra convexiusculci, latere postico utriusque valvte carinato; de- 



pressione lavi, cordatd, ad latus posticum umbonum ; impressioni- 



bus muscular ibus profundis ; long. y*V» loi- ,V> cdt- tV* 



Shell thick, subtriangular, insequivalve, transversely ribbed ; left valve 



but slightly convex, posterior side of both valves carinated, with a 



smooth cordate depression on the same side of the umbones ; muscular 



impressions deep. Although the smallest species we have seen, it is 



probably the thickest of the genus. 



Anatina ovalis. 



Tab. Supp. xliii. f. 7, 8. 



A. testa inmquivalvi, tenui, pellucidd ; latere postico hrevi, truncato ; 

 valvd dextrd convexd, margine superiors sulcata, marginem injlexum 

 alterius valva recipiente ; valvd sinistra convexiusculd ; cartilagine 

 cardinis interna, obliqiiA, elongatd : impressione pallii sinu magno ; 

 long, f^, hi. y\, alt. f-^. 



Shell insequivalve, thin, pellucid, posterior side trimcated ; right valve 

 convex, superior margin sulcated, receiving the inflected edge of the 

 other valve ; left valve slightly convex. Hinge with an oblique elon- 

 gate internal cartilage. Sinus of the impression of the mantle large. 

 Now in the cabinet of Michael Bland, Esq . 



Anatina elongata. 

 Tab. Supp. xliii. f. 9, 10. 



.^. testa transversim elongatd, inaquivalvi, pellucidd ; sinu impressio- 

 nis muscularis pallii versus latu^ anticum clongato ; long. y\, lat. 

 -rV, alt. ^. 

 Shell transversely elongate, inaequivalve, pellucid, sinus of the im- 



