BIVALVE SHELLS. 275 



elevatis, crassiusculis, utrinque duplicibus in valvula dextra; 

 simplicibus in sinistra. 



Musculus fluviatilis, Gualt. Ind. Test. pi. 7- f. C, C. 

 Tellina amnica, Mull. Verm. Hist. ii. 205. no. 389 ] Zool. Dan. 

 Prodr. p. 246. no. 296/. 



Chemn. Conch, vi. 138. pi. 13. f. 134. 

 Wood, Gen. Conch, p. 153. no. 19. pi. 47. f. 6 ; Ind. Test. 

 pi. 3. f. 19. 

 Tellina striata, Schrbt. Flussconch. p. 193. no. 15. 

 Tellina rivalis, Mat. ^ Rack. Linn. Trans, iii. 44. pi. 13. f. 37, 38. 



Donov. Nat. Hist, of Brit. Shells, ii. pi. 64. f. 2. 

 Cyclas palustris, Drap. Tabl. des Moll. p. 106. no. 3; Hist, des 



Moll. p. 131. pi. 10. f. 17, 18. 

 Cardium amnicum, Mont. Test. Brit. p. 86. no. 15. 



Turt. Brit. Fauna, p. 154, 

 Cyclas obliqua, Lamk. An. s. Vert. v. 559. no. 4. 

 Nilsson, Hist. Moll. Suec. p. 99. no. 4. 

 Alder, Trans. Nat. Hist. Soc. Newcastle, i. 41. f. 71- 

 Pisidium obliquum, C. PJeiff. Syst.An. p. 124. no. 1. pi. 5. f.l9, 20. 

 Cyclas amuica, Turt. Conch. Ins. Brit. p. 250. pi. 11. f. 15. 

 Pisidium amnicum, Jenyns, Trans. Cambr. Phil.Soc. i\. 309. no. 6. 

 pi. 19. f. 2. 



Gray, Turt. Man. ed. 2. p. 285. no. 120. pi. 1. f. 5. 

 Forbes ^ Hanley, Hist, of Brit. Moll. ii. 133. pi. 37. f. 8, 9, & 

 pi. O. f. 8, 

 Pera fluviatilis. Leach, Mus. Brit, (teste Jenyns, Cambr. Phil. Soc. 



iv. 310) ; Moll. Brit. Syn. ed. Gray, p. 292. no. 3. 

 Pera Henslowiana, Leach, Bi-it. Mus. {teste Jenyns, loc.cit.Y>.3\0) ; 



Moll. Brit. Syn. p. 291. no. 1. 

 Pisidium iuflatura, Megerle in Porro, Malac. Comasea, p. 121. 

 no. 109. pi. 2. f. 13. 



Villa, Dispos. Meth. Conch, p. 44. 

 Pisidium Pfeifferi, Ziegler (sec. Stentz) in Porro, Malac. Comasea, 



p. 121. 

 Pisidium palustre, Porro, Malac. Comasea, p. 122. no. 3. 

 Villa, Disp. Meth. Moll. p. 44. 

 Spinelli, Cat. Moll. Bresciana, p. 20. no. 136. 

 Cordula amuica. Leach, Moll. Brit. Syn. ed. Gray, p. 293. no. 1. 



Hab. In aquis dulcibus Europae. 



2. PiSUM CASERTANUM. B.M. 



p. testa crassa, ovali, tumidiuscula, valde obliqua, latere antico 

 posticum fere duplo superante, tenuissime transversim striata, 

 pellucida, cornea, fragili, apicibus integris, obtusissimis, saepius 



