NO. 2131. NEMATODE PARASITES OF RODENTS— HALL. 93 



Hosts. — Aimnospermophilus leucurus cinnamomeus, Callospermo- 

 philus lateralis. 



Location. — Cecum and large intestine. 



Localities. — United States (Pagosa Springs and Mack, Colorado), 



Type material. — No. 16582 U.S.N.M. (Bureau of Animal Industry 

 helminthological collection ) . 



Fig. 112.— OxYxmis triradiata. Posterior extremity of Fig. 113. — Oxyuris triradiata. Pos- 



MALE, VENTRAL VIEW. X 340. TERIOR EXTREMITY OF MALE, LATERAL 



VIEW. X 340. 



Fertilization of the Qgg appears to take place rather late. Al- 

 though I have an abundance of male and female material, includ- 

 ing some from cases of heavy individual infestation, I find no gravid 

 females. It is difficult to see the relation between the short, thick 

 spicule and the enormous vulvar labia; perhaps the labia enlarge 

 after fertilization. 



This species should be found fairly widely distributed. It occurs 

 in hosts of at least two genera and over a fairly wide range. Pagosa 

 Springs is near the southern edge of the State of Colorado and 

 Mack is near the middle of the western edge. 



