210 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 50. 



extends forward to the posterior extremity of the esophagus, and 

 the posterior uterus extends back almost to the anus. The eggs are 



55 to 60 ij. by 32 to 35 ^ in 

 diameter and contain an em- 

 bryo when oviposited (fig. 

 276). 



Host. — Geomys hreviceps. 



Location. — Stomach. 



Locality. — Norman, Okhi- 

 homa. 



Ty])e mateHal. — No. 17942, 

 U. S. N. M. (Bureau of Animal 

 Industry helminthological col- 

 lection). 



I .am indebted for this mate- 

 rial, as well as for much other 

 material not yet described, to 

 the courtesy of Mr. Herman 

 Douthitt, of the University of 

 Chicago. 



It should be noted that the 

 tj^pe-species of this genus has 

 two cervical papillae, the 

 esophagus is a third to a fifth 

 as long as the body, the vulva 

 is near the middle of the body, 

 the bursal alae are equal, and 

 each lobe of the lips bears-only 

 three teeth. It does not ap- 

 pear, however, that these dif- 

 ferences between the tj^De- 

 species and the sf>ecies in- 

 cluded here can be looked on 

 as of more than specific value 

 in view of the consistent re- 

 semblance in other respects. 



P. ascaroidea is a decidedly 

 larger species than P. muris, 

 but corresponding structures 

 in the two species are very similar, and the two species are very 

 closely related. 



Fig. 273.— Protospirura ascaroidea. Femalk. 

 v.. Vulva. 



