140 THE NAUTILUS. 



crispata Desh.), C. rigitla Dillw. 1817 ( V' rugosa Gmel. 1772, not 

 Linn. 1771), C. rugatina Heilp. and (7. strigillina Dall. Cyclinetta 

 tennis Reel. (Lucinopsis tennis}; CJtione cancellata L. ( Venus cancel- 

 /<), G. subrostrata Lam. ( V- beaui Reel.), C. mazyckii Dall ; C. 

 intapurpurea Con.; C. grus Holmes ; C. pygmaea Lam.; C. paphia 

 L.; C. latiiirata Conr. {V.varicosa So\vb.); Anomalocardiabrasiliana 

 Gmel. ( Venus flexuosa Born, not Linn., and V- macrodon Hanley are 

 syn.) A. cuneimeris Con. ( F- rostrata Sowb.); Venus mercenaria L.; 

 V- campechiensis Gmel. ( V- mortoni Con.), Liocyma fluctuosa Gould ; 

 Gemma gemma Tott.; G. purpurea H. C. Lea (G.concentrica Dall.), 

 and Parastarte triquetra Con. 



From tlie Pacific coast north of Mexico the following are received : 

 Dosinia ponderosa Gray (Pleistocene only, on the California coast), 

 Tramennella tantilla Gld.; Tivela (Pachydesma] stultorum Mawe. 

 (more familiarly known as Pachydesma crassatelhides Conr.), 

 Amiantis callosa Con.; Pitaria newcombiana Gabb.; Cytherea fordi 

 Yates ; Saxidomus nuttaUii Conr.; S. gigantea Desh.; Chione ftucti- 

 fraga Sowb.; C. undatella Sowb. ( V- simillima Sowb.); C. succincta 

 Val.; Venus kennicottii Dall ; Marcia kenneileyi Rve.; M. subdiaphana 

 Cpr.; Paphia (Protothaca~) slaminea Conr. The genus Paphia 

 Bolton 1798, replaces Tapes Megerle 1811, the latter is however 

 used as a sub-genus. Five varieties of P. staminea are recognized 

 Petiti Desh. (rigida Gould); laeiniata Cpr.; ruderata Desh.; orbella 

 Cpr., and sulculosa Dall. P. tenerrima Cpr.; Liocyma beckii Dall ; 

 L. viridis Dall ; L. scammoni Dall ; Venerupis lamellifera, Psephidia 

 lordi Baird (Psephis lordi}, P. ovalis Dall, and Gemma gemma Ton., 

 the latter introduced into San Francisco Bay on " seed " oysters. 



A number of forms on the Pacific coast are closely related to 

 species of the Atlantic fauna, and probably had a common ancestry 

 when the two oceans were connected at the isthmus. Dosinia 

 ponderosa " recalls somewhat the Atlantic D. contentrica ; " Tivela 

 byronensis Gray (7 1 . radiata Sowb.), is "the analogue of T. mac- 

 troides Born of the Antilles ;" Macrocallista squaUida Sowb., is the 

 analogue of M. macuJata of the Atlantic fauna, and CaHocardia 

 catharia Dall, is represented in West Indies by (\ aresta Dall and 

 Simpson ; Pitaria tomeana Dall is " the apparent analogue of P. 

 fulminata of the Atlantic fauna." P. (Hysteroconclta) lupanaria 

 Less, is '' a larger but less elegant analogue of the Antillean P. dione 

 L., easily recognized by the violet spots at the base of the spines; " 



