NO. 2131. NEMATODE PARASITES OF RODENTS— HALL. 191 



The life history and the site of infestation in the primary host 

 clearly relate this subfamily to the Spiruridae rather than to the 

 Filariidae, in spite of the absence of lips. 



Seurat (1914e, 1914/) regards Gongylonema as a lateral branch of 

 the Spiruridae arising from Protospirura. 



Genus GONGYLONEMA, Molin, 18S7. 



Synonyms. — Filar/a Mueller, 1787; Spiroptera Eudolphi, 1819; 

 MyzomlTnus Stiles, 1892. 



Generic diagnosis. — Gongyloneminae (p. 190) : Body filiform, 

 slightly attenuated toAvard the two extremities. Cuticle transversely 

 striated. Mouth small, elongated dorso-ventrally, and surrounded 

 by six small papillae. Anterior portion of body provided with lon- 

 gitudinal rows of cuticular bosses. Immediately behind the mouth 

 there is a dorsal and a ventral semilunar depression, simulating a 

 sucker. The esophagus consists of two distinct portions, a slender 

 anterior portion and a thicker posterior portion. The tail of the 

 male is curved ventrallj^ and provided with two asymmetrical alae 

 supported by elongated, claviform papillae, mostly arranged in pairs. 

 Vulva of female a short distance in front of anus. Eggs ellipsoidal, 

 containing w^ell-developed embryos when oviposited. 



Type-species. — Gongylonema 'muscull (Eudolphi, 1819) Neumann, 

 1894. 



ANALYTICAL KEY TO SPECIES OF GONGYLONEMA. 



1. Unrlescribed and dubious forms Gongylonema (?) species, p. 198. 



Described and recognizable forms 2. 



2. Males less than 10 mm. long and witli 14 pairs of caudal papillae ; females 



less than 25 mm. long Gongylonema musculi, ix 101. 



Males more than 10 mm. long and with not more than 12 pairs of caudal 

 papillae; females more than 50 mm. long 3. 



3. Males with 8 pairs of caudal papillae Gongylonema ncoplasticum, p. 193. 



Males with 12 pairs of caudal papillae Gongylonema brevisjnculum,]). 197. 



GONGYLONEMA MUSCULI (Rudolphi, i8ig) Neumann, 1894. 



Synonyms. — Filaria musculi Eudolphi, 1819 ; Gongylonema mini- 

 mum Molin, 1857. 



Specific diagnosis. — Gongylonema (p. 191) : Mouth orbicular. An- 

 terior portion of body provided with cuticular bosses. 



Male 8.8 mm. long. Anterior extremity attenuate and provided 

 with small cuticular bosses (fig. 248). Posterior extremity curved, 

 slightly attenuated ; the ventral surface forms a large elliptical de- 

 pression (fig. 249). There is a well-developed bursal membrane. 

 Fourteen pairs of clavate papillae, of which 10 are preanal and 4 

 postanal. There are two spicules. 



