NO. 2131. 



NEMATODE PARASITES OF RODENTS— HALL. 



89 



the uterus, the point of union being a short distance posterior of 

 the vulva. The uterus extends posteriorly to a point just anterior or 

 just posterior to the anus, where it forms the oviducts. Either the 

 uterus or the oviducts extend posterior of the anus (fig. 108), a dis- 

 tinctive point in distinguishing this species from its common associ- 

 ate, Oxyuris ohvelata. There is only a short, bluntly pointed clear 



Seg/on/na 



i/7/?a^. 



/^tenc/ofuti 



yiG.lOV.— 0XYURI3 TETRAPTERA. AN- 

 TERIOR EXTREMITY AND REGION OF 

 VULVA IN FEMALE, es., ESOPHAGUS; 

 es. huS), ESOPHAGEAL BULB; int., IN- 

 TESTINE; ov., OVARY; ui., UTEEUs; Fig. 108.— Oxyuris tetraptera. Posterior extremity of 

 v., VULVA. X 46. ' female. X 92.5. 



tail posterior of the reproductive structures, another feature which 

 distinguishes this species from O. ohvelata where there is a long tail 

 extending posterior of the anus. The eggs are of the typical Oxyuris 

 shape, 84 to 90 ^ long and 34 to 40 [jl thick. 



Hosts. — Mus musculus, Apodemus sylvaticus {Mus sylvatlcus), 

 Cricetus cricetus {Cricetus frumentarius, Cricetus vulgaris), Jacu- 

 lus jaculus {Dijms jaculus), Jacidus sagitta {Dipus sagitta). 



Location. — Large intestine. 



