NO. 2131. NEMATODE PARASITES OF RODENTS— HALL. 65 



it should be noted, is one without a chitinous margin, and therefore 

 of relatively weak development. 



Family OXYUKIDAE Cobbold, 1864. 



Family diagnosis. — Ascaroidea (p. 39) : Meromyarian. Mouth 

 with simple, usually inconspicuous lips. Male usually with one 

 spicule, at times reduced, imperfectly chitinized or absent. Caudal 

 extremity of female much elongated and subidate. Vulva anterior. 

 Eggs characteristically flattened on one side. 



Type-genus. — Oxyuris Rudolphi, 1803. 



Seurat (19155) states that the Oxyuridae, although considered 

 by most authors as belonging with the Ascaridae, are very distinct 

 and should be considered as a special group having the same origin 

 as the Heterakidae, but having evolved independent of the latter. 

 The Ascaridae, on the contrary, he would consider as the extreme 

 type of one ramification of what he calls the phylum Heterakidae. 



OXYIJI?,Ilsr.A.E: Hall, 1916, new subfainily. 



SubfaTnily diagnosis. — Oxyuridae (p. 65) : JNIales with one spicule, 

 at times lacking or imperfectly chitinized. 

 Type-genus. — Oxyuris Eudolphi, 1803. 



ANALYTICAL KEY TO GENERA OF OXYLTRInAE. 



1. Males with a longitudinal row of transverse comblike euticular structures 



on the ventral surface Dcrmatoxys,-^.^^). 



Males without such structure Oxyuris, p. 65. 



Genus OXYURIS Rudolphi, 180S. 



Sy7ionyms. — Oxyurus Lamarck, 1816; Lepturis Schlotthauber, 

 1860; Dermatoxys Schneider, 1866; Oxiurus Sonsino, 1878; Oxyurus 

 Rudolphi, 1803, of Brumpt, 1910; Syphacia Seurat, 1916; FuscurcUa 

 Seurat, 1916, 



Generic diagnosis. — Oxyurinae (p. 65) : Mouth naked or sur- 

 rounded by slightly salient lips. Esophagus long, followed by a 

 bulb, usually quite distinct. Males small and of relatively rare occur- 

 rence; provided with one spicule, which may be imperfectly chitin- 

 ized or not developed. One or more pairs of papillae in the vicinity 

 of the cloacal aperture. Females have the caudal extremity greatly 

 elongated and subulate. There are two ovaries. The vulva is located 

 in the anterior portion of the body as a rule. The eggs are elon- 

 gated, thin shelled, asymmetrical, flattened on one side and ending 

 in rounded points. Embryo may or may not be formed at oviposi- 

 tion : In 0. mvipara some females are oviparous and some viviparous. 



Type-species. — Oxyuris equi (Schrank, 1788) Blanchard, 1849. 



10600°— Proc.N.M.vol.50— 16 5 



