TRICHOSOMOIDINAE 239 



tudinal " bacillaiy band " may be present. iSpicule long and 

 slender, with a protrusible sheath, the outer surface of which, 

 when protruded, may be smooth or spiny. Tail of male may 

 be faintly alate. Eggs lemon-shaped, with polar opcrcula. 



Hab. Alimentary canal of Vertebrates. 

 Genotype : C. tumida Zeder, 1803 (= capillaris Rudolphi, 

 1809). 



Zeder, 1800, Erster Nachtrag zur Naturg. der Eingeweide- 

 wiirmer, Leipzig, 5 ; 1803, Anleitung zur Naturg. der Einge- 

 weidewiirmer, Hamburg, 61 ; Rudolphi, 1809, Entozoorum . . . 

 Historia NaturaUs, i, 86; Hall, 1916, Proc. U.S. Nat. Mas., 

 1, 33. 



3. Hepaticola Hall, 1916. 



Oesophageal portion of body shorter than posterior portion, 

 which is only slightly thicker. " Bacillary band " apparently 

 absent. Spicule absent, but a membranous sheath present. 

 Eggs with polar opercula, and shell (in genotype) apparently 

 striated in optical section. 



Hab. Liver of Mammals. 



Genotype : H. [Trichocephalus] hepatica (Bancroft, 1893). 



Bancroft, 1893, Journ. dh Proc. R. Soc. N.S.W., Sydney, 

 xxvii, 86; Hall, 1916, Proc. U.S. Nat. Miis., 1, 30. 



Subfam. 3. TRICHOSOMOIDINAE Hall, 1916. 



Male without spicule or spicule-sheath, and parasitic in the 

 vagina or uterus of the female. Eggs thick-shelled, with polar 

 opercula, and containing embryos when laid. Development 

 direct. 



1. Trichosomoides Railliet, 1895. 



Syn. Trichodes v. Linstow, 1874, nee Herbst, 1792. 



Oesophageal region of body not markedly more slender than 

 posterior region. " Bacillary band " apparently absent. 



Hab. Urinary organs of Rodents (one species known). 

 Genotype : T. [Trichosoma] crassicauda (Bellingham, 1840). 



Bellingham, 1840, Mag. Nat. Hist., London, iv, 349; 

 Railliet, 1895, Traite de Zoologie medicale et agricole, Paris, 

 1302; HaU, 1916, Proc. U.S. Nat. Miis., 1, 12. 



