\. 



TERRESTRIAL 



AIR-BREATHIXG MOLLI'SKS 



THE UNITED STATES, &c. 



X^ 



:w 



I ACADEMV OF NATURAL fSCIENCfS \ 



Pre*efUed by- i It t Exec ittaj'f ofDr3innft 



<: 7- -tc t: ard^T7re With UcS Vcll . J. 



ORDERED TO BE SOLD 



BT THE 



Acad.Vat.Stiences 



OF PHlL^bA. 



April 23, 1882. 



