A NEW NEMATODE, NE:^IAT0DIIIUS ANTILOCAPEAE. 

 FROM THE PRONG-HORN ANTELOPE, WITH A KEY 

 TO THE SPECIES OF NEMATODIRUS 



By Emmett W. Price 



Associate Parasitoloylst, Zoological Dixnsion, Bureau of Animal Industry, 



United States Department of Agriculture 



The nematode described in this paper was collected by the writer 

 from the small intestine of a prong-horn antelope Antilocapra 

 amep'icana which died in the National Zoolocrical Park, Washington, 

 D. C. This animal, a recent accession, was obtained from the west- 

 ern part of the United States. In view of the fact that wild rumi- 

 nants often serve as hosts for certain parasites of domestic animals, 

 it is not unlikely that this nematode may also occur in cattle, sheep, 

 or goats in certain parts of this country. 



This nematode belongs to the genus Nematodirus Ransom, 1907, 

 but it possesses characters which differ from those of any existing 

 species of the genus. It is therefore considered as new and tlie name 

 N ematoddrus antUocaprae is hereby proposed. 



NEMATODIRUS ANTILGCAPRAE, now species 



Diagnosis. — Nematodir^us. — Characters of the genus. 



Body long and slender, pinlc in color when fresh, and gradually 

 tapering toward the anterior extremity'. The cuticle of the head is 

 inflated asymmetrically, but no striations appear to be present. Cir- 

 cumoral papillae present. Cervical papillae not apparent. The 

 excretory pore is situated at the junction of the esophagus and in- 

 testine. The esophagus measures about 450 to 495;^ in length. 



Male 13 to 16 mm. long and with a maximum thickness of about 

 140|U,. The bursa (figs. 1 and 2) is composed of two large lateral 

 lobes and a smaller dorsal lobe. The dorsal lobe is set off from the 

 lateral lobes by moderately deep indentations. A deep median in- 



No. 2694.— Proceedings U. S. National Museum, Vol. 71. Art. 22 



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