274 BIVALVE SHELLS. 



in valva dextra dentem unieum modo simplicem, modo eom- 

 plexum praebente, inter dentes duos obliquos in altera valva re- 

 ceptum ; dentibus lateralibus angustis, depressis, elongatis, in 

 utraque valva lamelliformibus ; ligamentum breve, angustum, 

 externum ; impressio pallii simplex, postice minime excavata. 



Tellina, MiilL (1774) Verm. Hist. p. 205. 

 Cardium, PoU (1791), Test. utr. Sicil. i. 65. 



Mont. (1803) Test. Brit. p. 86. 

 Cyclas, Drap. (1801) Tabl. des Moll. p. 106 ; (1805) Hist. des 

 Moll.^. 131. 



Lamk. (1818) An. s. Vert. v. 559. 

 Pisum, Meg. (1811) Entw. p. 57 (non Linn.). 



Gray (1847), Proc. Zool. Soc. p. 184 ; Ann. 8f Mag. N. H. 

 xi. 34. 

 Pisidium, Pfeiffer, Syst. Anord. p. 120. 



Jenyns{\m'2), Cambr. Phil. Soc. iv. 300. 



Gray (1840), Turt. Man. ed. 2. p. 285. 



Forbes ^ Hanley (1849), Hist. ofBrit. Moll. ii. 130. 

 Galileja, Costa (1839), Corresp. Zool. 



Phil. (1844) Enum. Moll. Sicil. ii. 214. 

 Pera, Leach, MSS. (1819) fide Gray, Turt. Man. p. 282 (1840); 



Syn. Moll. Brit. (1852) ed. Gray, p. 291. 

 Euglesa, Leach,MSS. (1819) fide Gray, Turt. Man. p.282 (1840) ; 



Syn. Moll. Brit. (1852) p. 291, ed. Gray. 

 Cordula, Leach (1852), Syn. Moll. Brit. p. 292, ed. Gray. 



1. Synopsis Specierum. 



1. Species Europseanae, 1-11. 



2. Africanse, 12-15. 



3. Americae septentrionalis, 16-23. 



4. Americae meridionalis, 24-30. 



5. Australienses, 31, 32. 



6. Species dubia^, 33-36. 



1. Species EuropceancB. 



1. PlSUM AMNICUM. B.M. 



P. testa subovato-trigona, insequilaterali, veutricosa, eleganter 

 striato-costulata, cinereo-luteola, aliquautisper nigricante zo- 

 nata ; umbonibus parvis, obtusis, lan'iusculis ; dentibus cardi- 

 nalibus in angulum acutum dispositis ; dentibus lateralibus 



