NORTH AMERICAN CONCHOLOGT. 



99 



Page, 



20 



20 



20 

 20 

 21 



Tellina fragilis. 



Venus fragilis Fabr. 

 Cryptodon flexuosum. 



C flexuosum Turt. ? 

 Cyclas Steenbuchii MolL 

 Pandorina arenosa Moll. 

 Thracia myopsis Beck, 



21 



My a tnincata Lin. 



arenaria Lin. 

 Hiatella arctica. 



Mya arctica Fabr, 

 hyssifera Fabr. 

 Teredo navalis Lin. ? 



TUXICATA. 



21 Chelyoaoma Macleayarram 



Brod. h Sowh. 



21 Cynthia glutinans Moll. 



22 Ascidia monoceros Moll. 

 22 pyriformis RatJike. 



22 villosa Fabr. 



22 quadridentata Lin. 



22 xustica Lin. 



22 Ascidia ecMnata Lin. 



22 concMlega Mall. 



22 complanata Fabr. 



22 lurida Moll. 



22 Clavelina crystallina Moll. 



22 Boltenia reniformis M'Leay. 



Ascidia clavata Fabr, 

 22 ciliata Moll. 



BRACHIOPODA. 



23 TereTjratula psittacea Lam. 



23 Doris fasca Fabr. 



(There are also diagnoses of undetermined nudibranchiate Gasteropods. 

 — W. G. B.) 



Conrad. — Description of three new Species of Unio from the 

 Rivers of the United States : by T. A. Conrad. (From Journ. 

 Phila. Acad, Nat, Sci., vol, viii, 1842.) 



Page. Name. 



178 tJnio perplicatUB Conrad. 



179 nodiferus Conrad. 

 179 parallelus Conrad. 



Locality. 

 Jackson, La. 

 Jackson, La. 

 Jackson, La. 



Philipps. — Description of a new American Species of the 

 Genus Helix: by J. S. PniLippa (From same.) 



Page. 

 182 



Name. 



HelLz lasmodon Philipps. 



Locality. 



Alabama. 



