HELIGMOSOMINAE 189 



5. Nippostrongylus Lane, 1923. 



Cuticle transversely striated and with ten prominent longi- 

 tudinal ridges. Cuticle of head inflated. Cervical papillae 

 absent. Bursa of male with a small dorsal lobe and two 

 asymmetrical lateral lobes, the right being larger than the 

 left. In the left lobe the ventro-ventral, latero-ventral, 

 antero-lateral and medio-lateral rays are all thin, tapering 

 and approximately equally separated from each other. The 

 postero-lateral ray is much stouter, strongly divergent and 

 recurved dorsally towards its tip. In the right lobe the 

 ventral rays are thin, the ventro-ventral being divergent 

 from, and shorter than, the latero-ventral, which is closely 

 applied to the antero-lateral ray. The antero-lateral and 

 medio-lateral rays are stout and closely applied to each other. 

 The postero-lateral ray is short, very slender and divergent. 

 The externo- dorsal rays are within the dorsal lobe and are 

 equal, short and slender, arising high up on the median dorsal 

 stem. Dorsal ray fairly thick, bifurcating distally, with a 

 pair of accessory branches just in front of the bifurcation. 

 Its terminations are bidigitate or tridigitate. Spicules simple, 

 rod-shaped. An accessory piece present. 



Hab. Alimentary canal of Rodents (one species known). 



Genotype : N. [Heligmosomum] muris (Yokogawa, 1920). 



Yokogawa, 1920, Joimi. Parasitol, vii, 29 ; 1922, Parasitol, 

 xiv, 127 ; Lane, 1923, Parasitol., xv, 360. 



6. Viannaia Travassos, 1914. 



Body spirally coiled. Cuticle with faint transverse stria- 

 tions but without longitudinal markings, and enormously 

 thickened, especially in the male. Cuticle of head inflated. 

 Lateral lobes of bursa slightly unequal. Ventral rays parallel. 

 Lateral rays more or less equal, diverging at their tips. 

 Externo-dorsal rays originate high up on the median dorsal 

 stem. Dorsal ray relatively long, cleft in its distal third. 

 Its terminations are tridigitate. Spicules equal or subequal, 

 hooked at their tips. Accessory piece present or absent. 



Hab. Intestine of Marsupials, Edentates, Insectivores and 

 Rodents. 



Genotype : F. viannai Travassos, 1914. 



Travassos, 1914, Brazil Medico, Rio de Janeiro, xxviii, 326 ; 

 1921, Mem. Inst. Oswaldo Cruz, Rio de Janeiro, xiii, 96; 

 Hall, 1916, Proc. U.S. Nat. Mus., 1, 149, 158. 



7. Viannella Travassos, 1920 (?). 

 Body sometimes spirally coiled. Cuticle slightly swollen, 

 with transverse striations. Cuticle of head inflated. Bursa 

 large. Ventro-ventral ray shorter than, and divergent 



