BIVALVE SHELLS. 273 



conspicuo; cardine angustissimo bidentato, dentibus exiguis, 

 lateralibus parvis, antico paulo majore. 



Sphaerium Novae Zelandits, Desk. Proc. Zool. Soc. 1854. 



Hab. Nova Zelaudia; Nova Hollandia. 



46. Sph^rium egregium. 



S. testa ventricosa, transversa, oblonga, subsequilaterali, trans- 

 versim tenui-lirata ; apicibus parum elevatis, tumidis ; epider- 

 mide viridi corneo fusco zonata, plerumque Cycl. cornese siniili. 



Cj'clas egregia, Gould, Proc. Bost. Nat. Hist. Soc. iii. 2.92 ; 

 U?iit€d States Explor. Exp. Moll. p. 425. f. 526. 



Hab. In fluvio Himteriano Novae HoUandiae. 



7- Species dubice. 



47. C\ clas globosa, Megerle (non D' Orb.),inA. SfJ. B. Villa, Disp. 

 Syst. Conch, p. 44. 



Hab. Sangobard (Villa). 



48. Cyclas orbicularis (non C. orbicularia, Rcemer), Linsley, Cat. 

 of the Shells of Connecticut, Amer. Journ. xlviii. 276. 



Hab. America septentrionalis ; East Haddam {Linsley). 



49. Cyclas lutea, Ziegler, in Anton, Verz. der Conch, p. 14. no. 51 1 . 

 Hab. ? 



50. Cyclas Steinii, Schmidt, Zeitschr.f. Malak. no. 8, 1850, p. 118. 

 Hub. ? 



51. Cyclas truncata, Linsley, Amer. Journ. xlviii. 276. 



Hab. America septentrionalis j Stonington, Stratford et Strat- 

 field {Linsley). 



Genus 6. PISUM. 



Animal ovato-rotundatum, inaequilaterale, saepius turgidum ; 

 pallium simplex, antice inferneque apertum, postice in trachea 

 unica terminatum ; pes lingaiformis, compressus, apice acutus 

 vel subcylindraceus ; labiorum appendices breves, angustae ; 

 branchiae inaequales, latae, transversim oblique striatae, subplicatae, 

 postice inter se conniventes. 



Testa minima, tenuis, inaequilateralis, ovata vel subrotunda, 

 subglobosa, laevigata substriatave ; cardine angusto, dentato, 



12** 



