U. S. NATIONAL MUSEUM 



PROCEEDINGS. VOL. 75. ART. 18 PL. S 



y, 



C^ ' 



/yA 



o^- 



3^ 



ex/>. 



33. 



3J. 



2 mm 



HETEROBILHARZIA AMERICANA AND PARASCH ISTOSOMATIUM ANHINGAE 



FOH EXPLANATION OF PLATE SEE PAGE SS 



