THE NEMATODE FAMILY GNATHOSTOMID^. 251 



"Length of the female six lines to an inch ; breadth to one 

 qiiavterof a line; male from one-lialf to three-fourths of the size. 



" Frequent in the stomach of Emys serrata, Emys reticulata, 

 Gistado Carolina, and Klnosterii;um pennsylvanicwtit,, adhei'ing to 

 the mucous membrane in the same manner as Fhysaloptera 

 constricta" {vide infra, ]D. 272). 



I'he general appearance, the shape of the lips, the "funnels" 

 of the caudal papilla3 in the male, and the habitat and hosts all 

 suggest that this species is either identical with or closely allied 

 to Spiroxys contorta, but since the type of Leidy's species cannot 

 now be traced, the question must remain a,n open one. 



With i-egard to tlie Spiroxys contortiis (Rud.) of Seurat (1918), 

 from the African tortoise, Clemmys leprosa, we find the descrip- 

 tion of this form somewhat difficult to understand. If our 

 interpretation of it is correct, Sen rat's worm difi'ers from the 

 European species in the following points : — 



(1) the presence of an internal tooth on each lobe of each lip; 



(2) the presence of a pair of large papillae on the middle lobe 



of each lip, instead of one small papilla ; 



(3) the presence of an adanal, lateral pair of genital papillae 



in the male ; 



(4) the presence of an accessory piece in the male. 



Specific Diagnosis. 



Spiroxys contorta (Rud.. 1819). 



A slender Spiroxys; the lips without special armature, the tips 

 of the dorsal and venti-al lobes, especially their pulp, hooked 

 posteriorly; spicules ending in a, very fine point; caudal notch 

 of female relatively conrse. 



2. Spiroxys gangetica *, sp. n. (Text-figs. 4-6; PI. II. 

 'figs. 6-10.) 



We have examined two batches of nematodes belonging to this 

 species, the one collected by Mr. Southwell from a host indentified 

 by him as Trionyx gangeticus, iind the other collected by one of 

 us (C. L.) from a tortoise killed in the Ganges delta, probably 

 Trionyx gangeticus. The two sets of speciujens are specifically 

 identical. 



This worm is stouter than the genotype. The head end tapers 

 much more graxlually than the tail and is usually bent at an angle. 

 Close to either edge and near its base each lobe of either lip bears 

 a cuticular tooth on its inner surface (PI. II. figs. 6 & 7), 

 Each lip, that is, has six teeth in addition to that characteristic 

 of the genus. In dorsal (or ventral) view the inner face of the 

 dorsal (or ventral) lobe is fiattened against its fellow of the other 

 lip, the cuticular teeth appearing from beneath near the angles 



* For specific diagnosis, see p. 253. 



