89 



whether it is realiv diflin^l. It is however proper to re- 

 mark, that the young of the amnicum extrafted IVom the 

 parent (hell, though not much inferior in fize, ai'e always 

 more conipreiled. 



16. 

 Tellina lacuflris. GmeJ. Syji. p. 3242, — Turt. Lin. iv. p. 197. Lacustre. 

 Mulkr. vern:. p. 205. No, 3S9, 

 Chein. Conch, vi. t. 13. f 135. 

 Shroet Fhifsconck. p. 191. No 12. 



C with a fub-rhomboidal, thin, pellucid, fniooth (liell, 

 of a pale horn-colour, fometimes covered with a dark 

 brown epidermis; rather comprefled, particularly round 

 the margin : umbo central, fmall, but extremely promi- 

 nent, projefting beyond the commiOure, and when tlse 

 valves are clofed, and the fhell viewed fideways, exhibits a 

 cordiform fhape; hinge (light, teeth fmall, in each valve 

 a primary tooth, one of which is plain, the other bifid; 

 with lateral teeth in both valves, one on each fide the 

 hinge, and two additional very minute lamime in one 

 valve, fituated as in the preceeding fpecies. Length 

 three-tenths of an inch; breadth four-tenths. 



We v/ere firft favoured with this by Mr. Swainson, in 

 whofe cabinet of BriUjh fhells were feveral under the 

 title of Tellina coviprejja. This gentleman informed us 

 it was found in a river near Buljirode, and that he had 

 taken it in the river near Longford, but that it was fcarce. 



N Since 



