118 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 50. 



and attains a maximum thickness of 205 to 275 /*. The nerve ring 

 is 430 to 490 fi from the anterior end of the body. The anus is 300 

 to 350 fi from the end of the tail. The vulva is a transversely 

 elongated slit with prominent lips and is 645 to 860 ^u, from the end 

 of the tail. The vagina is 380 to 390 /x long and is directed anteriorly 

 from the vulva, the anterior end bending in a somewhat lateral 

 direction to join the ovijectors. The combined lengths of the muscular 

 portions of the ovijector are 

 about 675 to 700 jn. One is 

 directed anteriorly from the 

 common central portion, the 

 other is directed posteriorly, /^.. 



^ 



Fig. 144.— Ransomus rodentorum. 

 Bursa, dorsal view, d., Dorsal ray; 



e.d., EXTERNO-DORSAL ray; I., POSTERO- 

 LATERAL AND MEDIO-LATERAL RAYS; I. t!. , 

 LATERO-VENTRAL RAY; V. V., VENTRO- 

 VENTRAL RAY. ENLARGED. 



Fig. 145.— Ransomus rodentorum. Bursa, lat- 

 eral VIEW, d., Dorsal ray; e. d., externo- 

 DORSAL ray; e. I., exteeno-lateral ray; I. v., 

 latero--\t;ntral ray; m. I., medio-lateral ray ; 

 p. I., postero-lateral ray; v. v., VENTRO-'VENT- 

 RAL RAY. Enlarged. 



but proceeds only a short distance before turning anteriorly. The 

 eggs are ellipsoidal and are 100 to 105 by 55 to 60 fi in diameter. 

 Eggs not yet segmenting when oviposited. 



Host. — ThoTnoTnys fossor. 



Location. — Cecum; occasionally in small intestine. 



Localities. — Ruxton Creek (El Paso County, Colorado) ; Middle 

 Brush Creek (Gunnison County, Colorado) ; and Crested Buttes, 

 Colorado. 



Type matei-ial. — No. 16181, U.S.N.M. (Bureau of Animal In- 

 dustry helminthological collection). 



