NORTH AMERICAN CONCHOLOGY. 



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Tellina fragilis. 



Venus fragilis Fabr. 

 Cryptodon flexuosum. 



C. flexuosum Turt. ? 

 Cyclas Steenbuchii Moll. 

 Pandorina arenosa Moll. 

 Thracia myopsis Beck. 



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Mya truncata Lin. 



arenaria Lin. 

 Hiatella arctica. 



Mya arctica Fabr. 

 byssifera Fabr. 

 Teredo navalis Lin. ? 



TUMCATA. 



22 Ascidia echinata Lin. 



22 conchilega Miill. 



22 complanata Fabr. 



22 lurida Moll. 



22 Clavelina crystallina Moll. 



22 Boltenia reniformis M'Leay. 



Ascidia clavata Fabr. 

 22 ciliata Moll. 



BRACHIOPODA. 



23 Terebratula psittacea Lam. 



23 Doris fusca Fabr. 



(There are also diagnoses of undetermined nudibranchiate Gasteropoda. 

 — W. G. JB.) 



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

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

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



Page. Name. 



178 TJnio perplicatus 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. Philipps. (From same.) 



Page. Name. 



182 Helix lasmodon Philipps. 



Locality. 

 Alabama. 



