48 PROCEEDINGS OF THE NATIONAL MUSEUM vol.81 



a trifle cephalic in old ones, but in no case was it observed more than 

 1 mm from the middle. The female tail varies from 0.3 to 0.5 mm 

 in length. The ova measure QOn to 70/x, wide by 100^ to IZOfx long. 



Host. — Terrafene Carolina triunguls. t 



Location. — Rectum. 



Locality. — Houston, Tex. 



Type specimens. — U.S.N.M. Helm. Coll. No. 3173; paratypes, No. 

 3174. 



Remarks. — These nematodes occurred in large numbers in the recta 

 of nearly all the hosts examined. They are remarkably similar to 

 Cruzia tentaculata., for careful study has shown only one constant 

 difference between the two forms. The female tail of Cruzia testu- 

 dinis varies from 0.3 to 0.5 mm in length, and its ratio to the total 

 length varies from 1 : 28 to 1 : 40. The female tail of Cruzia 

 tentaculata varies from 0.6 to 1 mm, its ratio to the body length 

 varies from 1 : 14 to 1 : 18. There are also average differences in 

 the length of the esophagus, but here the variation is too great for 

 the character to be of any importance. So striking is the similarity 

 between these two species and so slight are the differences that the 

 writer would still consider them to be cospecific were it not for the 

 great phylogenetic separation of the hosts. 



Family OXYURIDAE Cobbold, 1864 



Subfamily Oxyurinae Hall, 1916 

 Genus PHARYNGODON Diesing, 1861 



This genus has been unlmown in North America until very re- 

 cently. Walton (1929) described P. hratrachiensis from the tadpoles 

 of Rana pipiens. Walton, however, had only female specimens on 

 which he based his description, and while they are very similar to 

 the females of Pharyngodon, they show certain peculiarities not 

 found in other members of the genus. 



With this possible exception the genus is represented only in 

 lizards. The excretory pore and the vulva are unusually posterior in 

 position, and the plugs in the eggs are in the inner instead of the 

 outer membrane. Most of these differences were pointed out by 

 Walton, and while they do not necessitate the removal of the worm 

 from the genus at this time, the discovery of the male may make 

 such a change necessary. 



PHARYNGODON WARNERI, new species 

 Plate 4, Figures 5, 6 



Specific diagnosis. — Pharyngodon : White, stout nematodes, usually 

 showing marked cross striations of the cuticula near the cephalic end 



