NO. 2131. NEMATODE PAR AS^TTE."^ OF RODENTS— HALL. 219 



wide pharynx. The walls of the pharynx are marked by cuticular 

 ridges in the form of both spirals and rings and extending the length 

 of the pharynx. The tail of the male is twisted spirally and fur- 

 nished with a narrow symmetrical bursa supported by four pairs 

 of preanal papillae. Spicules long and unequal, the left spicule 

 about five times as long as the right. Vulva somewhat posterior of 

 the middle of the body. Eggs smooth, with thick shells, and con- 

 taining embryos when oviposited. Endoparasitic in the stomach 

 of Suidae and rodents. 



T yp e- S'p ecie s . — Physocephdlus sexalatuft 

 (Molin, 1860a) Diesing, 1801. 



PHYSOCEPHALUS MEDIOSPIRALIS (Molin, i86oa) Hall, 1916. 



Synonyms. — Spii'optera mcdiospiralis Molin, 

 ISOOc/; Spiroptera taplri-arnericani in M. C. V. 

 of Molin, 18C0c?; Spiroptera caviae aguti in M. 

 C. V. of Molin, ISGOrt; Spiroptera chnsoptera 

 Molin, 1858rf., of von Drasche, 188-2. fig. 287.-PHYsocEPHALr3 



CI .,,7. . 7-, 7 77 / ti-ioX MEDIOSPIRALIS. HEAD, 



bpecifiG diagnosis.— Fhysocephaius (p. 218): viewed from the front. 

 Body tAvisted spirally in the middle, attenuate x 280. after von 

 anteriorly and enlarged posteriorly. Head dis- 

 tinct from body and with inflated cuticle (fig. 287). Pharynx with 

 rings and spirals. Anterior extremity gradually attenuate and trun- 

 cate at head end. Three lateral alae on each side, the median the 

 larger, and all transversely striated. Posterior extremity thickened. 



MoJe 26 to 36 mm. long and 400 [J^ thick. Posterior extremity 

 twisted in a spiral of three turns and terminating obtusely. Bursal 

 membrane sustained by four papillae. One spicule is long, thick, and 

 tubular; the other spicule not noted. 



Female 40 to 46 mm. long and 500 [x thick. Posterior extremity 

 thickened and only slightly bent ; terminates in an obtuse, umbonate 

 tip. Anus near the tip of the tail. Vulva not observed. 



Host. — iJasypTOcta aguti {Dasyprocfa agouti). 



Location. — Stomach. 



Locality. — Brazil. 



In the above description the statement that the pharynx has rings 

 and spirals is based on a statement that the body is so marked. It 

 is very easy to get the impression that the markings of the pharynx 

 are on the body in mounts of Pkysocephalus and Ay'duenna. More- 

 over, such spiral markings would be highly exceptional in the body, 

 whereas they fit with the rest of the description if regarded as 

 pharyngeal markings. 



Von Drasche (1882) regards Spiroptera mediospiralis Molin, 

 1860«, and Spiroptera chrisoptera Molin, 1858«, both of which 

 species have been reported from Tapirus americanus, as identical. 



