ZOOLOGICAL 



CONTRIBUTIONS 



S. S. HALDEMAN, 



Member of the Academy of Natural Sciences of Philadelphis 



No. 1.— Feb. 1842. 



ON SOME AMERICAN SPECIES OF 

 HYDRACHNID^. 



PHILADELPHIA ; 



ISSUED BY THE AUTHOR. 



E. G. Dorsey, Friuter, Library Street. 



