TWO NEW SPECIES OF NEMATODE WORMS OF THE 

 GENUS OSTERTAGIA FROM THE VIRGINIA DEER, 

 WITH A NOTE ON OSTERTAGIA LYRATA 



By G. DiKMANS 



Associate Parasitologist, Zoological Division, Bureau of Animal Industry 

 United States Department of Agriculture 



Through the courtesy of the Bureau of Biological Survey and of 

 the Pennsylvania Board of Game Commissioners, the writer was 

 afforded an opportunity to examine several abomasums of the Vir- 

 ginia deer {Odocoileus vi7'gi7iianus), from Pennsylvania. A total 

 of 16 abomasums were examined, and 11 of these contained nema- 

 todes belonging to the genus Ostertagia and representing two 

 hitherto undescribed species. 



Specimens of the first of these species were referred to the zoologi- 

 cal division by Dr. J. D. Jones, of the Pennsylvania Bureau of 

 Animal Industry, Harrisburg, Pa., in March, 1929, and later addi- 

 tional specimens of this species and specimens of the second species 

 were collected by the writer from material sent to the laboratory 

 for examination by representatives of the Pennsylvania Board of 

 Game Commissioners. 



OSTERTAGIA ODGCOILEI, new species 

 Plate 1 



SpecifiG diagnosis. — Ostertagia — Male: About T.5 mm. long- and 

 120/x wide just anterior to the bursa. Esophagus, 560/* long and 54ju. 

 wide at base. Head, 23/x, wide. The cervical papillae are situated 

 about 300ju, from the head end. The nerve ring is located slightly 

 anterior to these papillae. The spicules are 165jli long and are light 

 brown in color; they are divided distally into three processes, two 

 of which are ventral in position and one dorsal ; the dorsally directed 

 process is deeper in color than the remainder of the spicules and 

 terminates in a broad truncated end; the two other processes are 

 sharp-pointed; the outer ventral branch is the longest. There is 

 no gubernaculum. In the general arrangement of the rays of the 

 bursa, this species does not present any striking difference from other 

 members of the genus. The externo-dorsals are comparatively short 



No. 2872— Proceedings U. S. National Museum, Vol. 79, Art. 6 



5325 8—81 1 



