NO. 2131. 



NEMATODE PARASITES OF RODENTS— HALL. 



13 



TRICHOSOMOIDES CRASSICAUDA (Bellingham, 1845) Railliet, 1895. 



Synonyms. — Trlchosoma crassicauda Bellingham, 1845; Trichoso- 

 mum crassicauda (Bellingham, 1815) Eberth, 18G3; Trlchocephalus 

 crassicauda (Bellingham, 1845) Eberth, 18G3; Trichodes crassicauda 

 (Bellingham, 1815) von Linstow, 1874; Trlchosoma Tnurls decumani 

 Bayer of Stossich, 1890. 



S'pecifiG diagnos Is. — Trlchoso- 

 moldcs (p. 12) : Male and female 

 very dissimilar in size, the male 

 commonly found parasitic in 

 the vagina or uterus of the fe- 

 male. Anus terminal in both 

 sexes. 



Male 1.4G to 2.5 mm. long and 

 23 to 33 [x thick (figs. 9 and 10). 

 Anterior terminal portion of 

 esophagus devoid of cell body; 

 according to von Linstow 

 (1874), the portion of esopha- 

 gus surrounded by the cell chain 

 is equal in length to about half 

 the total body length. The in- 

 testine has numerous fine re- 

 fractive nuclei in its wall, these 

 being especially prominent in 

 somewhat macerated specimens. 

 There is no spicule, bursa, or 

 trace of copulatory organs of 

 any sort, a lack correlated vrith 

 the fact that the male lives in 

 the vagina and uterus of the 

 female. The single tubular 

 testis originates in the anterior 

 portion of the body and trans- 

 forms into the vesicula semi- 

 nalis which is filled with spermatozoa showing a small dark spherical 

 nucleus. 



Female 10.5 to 13 mm. long and attaining a maximum thick- 

 ness in the posterior portion of the body of around 200 [/. (figs. 10 

 and 11). Anterior 200 to 260 [x of esophagus devoid of a surround- 

 ing cell body, and followed by a short transitional portion where 

 there is a gradually enlarging protoplasmic structure surrounding 

 the chitinous central tube and continued by the cell body posteriorly. 



Fig. 9.— Tkichosomoides crassicauda. Male. 



