NO. 2131. 



NEMATODE PARASITES OF RODENTS— HALL. 



129 



fore 160 n from the tip of the tail. The length of the esophagus 

 is one-eighteenth of the total body length. The vulva is situated 

 posteriorly, dividing the body in the ratio of 37 : 11, and is therefore 

 2.4 mm. from the tip of the tail. The eggs are 62 fx long and 36 fx. 

 thick. 



Hos f. — L epus n ig r'lco Uis. 



Location. — Stomach. 



Locality. — Ranna, Southern Province, Ceylon. 



Von Linstow notes that this species is close to Trichostrongylus 

 retortaefornfiis., and while nothing is said of a gubernaculum and the 

 bursa rays are figured as of the same size throughout, it 

 probably belongs in Trichostrongylus. The spicule size is 

 large; perhaps it should be 68 n. 



TRICHOSTRONGYLUS FIBERIUS Barker and Noyes, 1915. 



SpecifiG diagnosis. — Trichostrongylus (p. 121) : Body 

 threadlike; anterior region greatly attenuated, body grad- 

 ually thickening toward the posterier end. 



Male 2.8 mm. 

 long with a body 

 diameter of 13 [x. 

 just behind the 

 head and of 90 \x. 

 just anterior of 

 the bursa. Bursa 

 with two wide 

 lateral lobes and 

 a narrow dorsal 

 lobe. " Lateral 

 lobes with t w o 

 wide, blunt, lat- 

 eral raj'S and one narroAv, pointed dorso-lateral and one ventro- 

 lateral ray." Spicules short and heavy (fig. 159). 



Female 4.7 mm. long, with a body diameter of 30 [k just behind the 

 head and of 135 ju at the level of the vulva. Vulva in the posterior 

 ninth of the body, 520 /x from the end (fig. 160). Anus 80 ju from the 

 posterior end of the body. Posterior end slightly curved and 

 pointed. Eggs oval, segmented (when oviposited ?), 59 by 36 [x in 

 diameter; shell thick. 



Host. — Ondatra zihethica {Fiber zihethicus) . 



Location. — Duodenum and cecum. 



Locality. — United States (Nebraska). 



Fig. 157.— Trichostrongylus pigmentatus. Bursa, dor.s.\l 

 VIEW. Enlarged. After von Linstow, 1904. 



10600°— Proc.N.IM.vol.50— 16- 



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