ART. 17 



PARASITES OF AMPHIBIA AND REPTILIA HARWOOD 



45 



FALCAUSTRA AFFINE (Leidy, 1856) 



Worms that I have taken from the ceca of several specimens of 

 Tei^apene Carolina triunguis agree very closely with the description 

 given by Boulenger except for size. As none of Boulenger's ma- 

 terial was fully mature, this discrepancy is rather to be expected. 

 In my material males 10 mm long and females 11.5 mm long were 

 not uncommon. 



FALCAUSTRA PROCERA (Canavan, 1929) 



I have taken specimens that agree very closely with Canavan's 

 description of this species from the rectum of Pseudeinys elegans. 

 Only in the length of the male tail is there a conspicuous difference. 

 Canavan gives the total length as 13 mm and the length of tail as 

 1.4 mm, but the tail of a specimen 13.8 mm long in my collection 

 measures only 0.75 mm. However, if one measures the male tail 

 figured by Canavan, he finds that its length falls very close to 0.8 mm. 



Canavan considers his species to be most closely related to Fal- 

 caustra testudinis Baylis and Daubney, but I find it very difficult to 

 distinguish it satisfactorily from S. afjine. As I have stated above, 

 fully matured specimens of S. afjine are much larger than those 

 which Boulenger described. Between these larger specimens and 

 S. -procera I could find only slight differences in lenglhs of the 

 esophagus and of the tail. These are certainly sufficient to warrant 

 the erection of a subspecies, but I have some little doubt if they 

 are of full specific value. Table 1 gives the more important meas- 

 urements and represents the extremes found in measuring' five 

 examples of each sex of each species. 



Table 1. — Comparison of measurements of Falcaustra affine and F. procera 



{five examples of each sex) 



FALCAUSTRA CHELYDRAE, new species 



Plate 4, Figure 4 



jSpecifiG diagnosis. — Falcaustra: A slender white nematode with 

 a finely striated cuticula. The mouth is surrounded by three large 

 lips each of which bears two forlced papiHae. The esophagus con- 



