50 CO^CHYLIX—DITHYRA. 15. 



hinge with a projectiug round spoon-shaped tooth in each valvey 

 and a cavity close to it. 



This shell so very much resembles some specimens of the 

 Hiatella minuta, that without an examination of the hinge it 

 might be easily overlooked for it. That Linne knew them ia 

 be distinct is evident, from his having placed them in two diffe- 

 rent genera, on account of the differences in the hinge 



15. LlSTEIi\—TURTON. 



Testa transversa, ovata, tsquivalvis, lateribus subhiantibus. 



Cardo dente cochleariformi cum denticulis adjectis : lateralis 



husnullis. Ligamentum externum. 

 Shell transverse, oval, equivalve, a little open at the sides. 



Hinge with a spoon-shaped tooth and additional denticles: 



lateral teeth none. Ligament external. 



This Family differs from the Anatina, in having a small tooth 

 or two in addition to the spoon-shaped ones : and from the genus. 

 Amphidesma in wanting the lateral teeth. 



It is named from Or. Martin Lister, the Coryphaeui of ali 

 ftystematic conchology. 



