44 PEOCEEDIISrGS OF THE NATIONAL MUSEUM vou 81 



identified with any known Polydelphis species, and because of the 

 immature condition of the worms it is believed better not to name 

 them at this time. A brief description is added, however, to aid 

 in their future classification. 



When alive the worms are light yellow. The cuticula is marked 

 with numerous fine longitudinal striations. 



Male : Length 35 to 40 mm ; width about 0.7 mm. The esophagus 

 is 2.5 mm long. The nerve ring is 1.2 mm from the anterior end. 

 The tail is 0.185 mm long and ends in a short spike about 25ju, long. 

 The spicules are equal, 0.4 mm long, and 25ja wide. There are two 

 pairs of lateral papillae placed just anteriorly to the base of the 

 tail spike, and two rows of papillae running from behind the anus 

 anteriorly. These rows are very irregular and 44 papillae could be 

 counted in one row, but only 23 in the other. 



Female : In only one specimen were the female genital organs suf- 

 ficiently developed to count the number of uteri. A description of 

 this one is given. Length 53 mm. Esophagus 2.6 mm long. Nerve 

 ring and excretory pore 1.2 and 1.85 mm, respectively, from the 

 anterior end. The vulva is 24.5 mm from the anterior end, and from 

 it the ovejector runs posteriorly for 0.55 mm before giving rise to 

 four uteri by dichotomous branching. 



Polydel/pliis anoura has been reported from several North Ameri- 

 can snakes, and by Baylis (1921) is doubtfully reported from the 

 above-mentioned host. The spicules, however, clearly separate this 

 form from P. anou7'a. 



Family KATHLANIIDAE Travassos, 1918 



Genus FALCAUSTRA Lane, 1915 



This genus has been considered a synonym of Spironoura by 

 many recent authors. Spironoura^ as erected by Leidy (1856), con- 

 tained two species, S. gracile^ type species, from the stomach of Emijs 

 serrata, and S. affine from the cecum of Cistodo Carolina. Only the 

 latter species has subsequently been found and redescribed. Bou- 

 lenger (1923) redescribed it under the name of Falcaustra chapini, 

 but Chapin found it to be the only parasite present in the ceca of 

 box turtles in the vicinity of Washington, D. C, and on the strength 

 of this evidence suggested that it was identical with Spironoura 

 a/fine. He further suggested that Falcaustra Lane should be con- 

 sidered a synonym of Spironoura Leidy, but since Leidy's species 

 gracile is the type, and this form has not since been studied, it 

 would seem premature to dispose of the genus Falcaustra as a syno- 

 nym of Spironoura. This opinion is further supported by an obser- 

 vation that Walton (1927) made on the existing Leidy collection of 

 nematodes. For these reasons the genus Falcaustra is here retained. 



