188 STRONG YLOIDE A 



S. polygynis Dujardin. The latter species he removed to 

 Travassos' genus Viannaia. Boulenger, however, has shown 

 that the species of Dujardin and v. Linstow are identical and 

 should be retained in Hall's genus Heligmosomoides. 



3. Nematospira Walton, 1923. 



Body spirally coiled. Cuticle of head inflated to form two 

 wing-like swellings, limited behind by an annular constriction 

 and showing transverse striations. Cuticle of body with 

 faint transverse striations and numerous (over twenty-five) 

 longitudinal ridges. Three small, poorly-defined lips present. 

 Cervical papillae absent or minute. Bursa indistinctly tri- 

 lobate. Ventral rays fused towards their bases, but rather 

 Avidely separated distaily. Lateral rays all arise from a 

 common trunk, but are well separated distally. Externo- 

 dorsal rays almost parallel, long, but not reaching the margin 

 of the bursa. Dorsal rays paired, very small, originating 

 from the bases of the cxterno-dorsal rays. Spicules long, 

 slender, usually twisted, grooved on their ventral surfaces. 

 An accessory piece present. Eggs with thin, rugose shells. 



Hab. Alimentary tract of E,odents. 

 Genotj'pe : N. turgida Walton, 1923. 



Walton, 1923, Journ. Parasitol., x, 59, 61. 



4, Heligraostrongylus Travassos, 1917. 



Cuticle transversely striated and with prominent longi- 

 tudinal markings, of which one appears as a dorsal ala. 

 Cuticle of head dilated. Bursa of male not distinctly separ- 

 ated into three lobes. Ventral rays short and divergent. 

 Postero-lateral ray longer than, and widely divergent from, 

 the remaining lateral rays. Externo-dorsal rays arise from 

 the cleft portion of the dorsal ray, and are fairly long and 

 slender but do not reach the margin of the bursa. Dorsal 

 ray cleft to its base, its divisions being the longest rays in 

 the bursa. One pair of short accessory branches present, 

 originating about half-way from the tips of the dorsal ray. 

 Spicules simple, filiform. Aw imperfectly-chitinized accessory 

 piece present. Anterior lip of vulva swollen into a pendulous 

 process which may cover the anus and extend beyond the 

 tip of the tail. 



Hab. Small intestine of Rodents (one species known). 

 Genotype : H. [Strongijlus] sedecimradiatus (v. Linstow, 

 1899). 



V. Linstow, 1899, Mitt. Zool. Mus. Berlin, i, 19 ; Travassos, 

 1917, Brazil Medico, Rio de Janeiro, xxxi, 3 ; 1921, Mem. 

 Inst. Oswaldo Cruz, Rio de Janeiro, xiii, 95. 



