Ksm-.l ( X-II.I..T 9, 1912. 



U. S. DEPARTMENT OF AGRICULTURE, 



BUREAU OF ANIMAL INDUSTRY. BULLETIN 158. 



A. D. MELVIN, CHIEF OF BUREAU. 



THE ROUNDWORMS OF DOMESTIC SWINE, 



WITH SPECIAL REFERENCE TO TWO SPECIES 

 PARASITIC IN THE STOMACH. 



BY 



WINTHROP D. FOSTER, 



Junior Zoologist, Zoological Division. 



WASHINGTON: 



GOVERNMENT PRINTING OFFICE. 

 1912. 



