BIVALVE SHELLS. 



187 



rnaximae, ovato-rotimdje, subfcquales ; sinus pallii magnus, elon- 

 gatiis, horizontalis ; ligamentum externum crassissiinum, elou- 

 gatum, semi-cylindraceura. 



Venus (spec), Sow. (1835) Proc. Zool. Soc. p. 42. 



D'Orb. (1839) Pal. Amer. Merid. p. IGO. 



Jonas (1844), Moll. Beitr. p. 14. 



PhiUppi (1846), Abbild. Conch, i. 

 Venerupis (spec), Deshayes (1839), Mag. de Zool. 



Grewingk (1848), Verh. Kais. Russ. SfC. p. 351. 



Middendorf {\S-i9), Malac. Ross. p. 567. 

 Tapes (spec), Soiverby (1852), Thes. Conch. 

 Saxidomus, Conrad (1837), Journ. Nat. Sci. Phil. 



Jay (1839 & 1851), Cat. Shells. 



Synopsis Specierum. 

 I. Species laevigatse, 1-6. 

 II. Species sulcatse, 7, 8. 



I. Species Icevigata. 



1. Saxidomus maximus. 



S. testa maxima, ponderosissiraa, oblongo-ovata, utrinque trun- 

 cato-rotundata, transversim sulcata, lutesceute ; apicibus ad | 

 lougitudinis sitis ; area lunulaque nullis ; ligamento niaximo, 

 prominente ; cardine tridentato ; pagina interna alba, postice 

 violaceo-suffusa ; margine integerrimo. 



Venus maxima, Anton, in Phil. Abbild. Conch, ii. pi. 6. f. 1 . 

 Tapes maxima, Sow.jun. Thes. Conch, p. 692. pi. 150. f. 127- 



Hob. Nova Hollandia, ad Portum Lowe dictum. 



2. Saxidomus giganteus. 



S. testa ovato-oblonga, insequilaterali, subcordiformi, transversim 

 striato-rugosa, postice hiante et subtruncata, cardine eroso, 

 nymphis magnis porrectis, marginibus integris. 



Venerupis gigantea, Desh. Rev. Zool. Soc. Cm. 1839, p. 359 ; 



Mag. Zool. Guerin, Moll. pi. 43 (1841). 

 PuUastra gigantea, Callow, Conch. Nom. p. 41. 



Hab. Mare Californiense. 



3. Saxidomus opacus. B.M. 



S. testa oblonga, subquadrata, turgida, concentrice substriata, 

 opaca, albida, pallidissime purpurascente ; latere buccali bre- 



