NO. 2131. 



NEMATODE PARASITES OF RODENTS— HALL. 



19 



the customary bacillary band. The hemispherical elevations noted 

 in the previilvar portion of the body are apparently to be seen only 

 in profile and are due to deep cuticular annulations. 



Yzd mm. 



Fig. 18.— TKiCHOsoMoroES crassicauda. Embeyo. 



Fig. 19.— Trichosomoides 



CRASSICAUDA. EmBEYO. 



After von LmsTow, 1882. 



Subfamily TRICHXJRIN^E RansoiTi, 1911a. 



Bynonym. — Capillariinae Railliet, 1915, in part. 



Subfamily diagnosis. — Trichinellidae (p. 9) : ISlale with one 

 spicule, or, exceptionally, Avith only a copulatory sheath. Eggs 

 lemon-shaped, the apertures at each end closed with opercular plugs. 

 Development, so far as known, direct and without intermediate host. 

 Egg development often slow. Eggs with thick shell; do not hatch 

 until swallowed by a suitable host. 



Tyjye-genus. — Trichuris Roederer, 1761. 



ANALYTICAL KEY TO GENERA OF TRICHUKINAE. 



1. Antei'ior esophageal region of body very slender and longer than the pos- 



terior portion, which is much thicker and contains tlie reproductive 



organs Triclmris, p. 20. 



Anterior esophageal portion of body shorter than, rarely equal to, the pos- 

 terior portion, which is only slightly thicker 2. 



2. Worms with spicule ; in digestive tract or urinary bladder, ducts, 



etc CapiUaria, p. 33. 



Worms without spicule ; in liver Hepaticola, p. 30. 



