24 PROCEEDINGS OF THE NATIONAL MUSEUM vol.81 



differences noted between the two lots of material could easily be 

 explained on the basis of age differences or individual variation. 

 When these forms were compared with Stafford's description of 

 M. occultum and Holl's description of Plogitwra scdannandra^ no 

 differences of importance could be noted. It is, therefore, probable 

 that Plagitura salamandra HoU, 1928, should fall as a synonym of 

 M anodistonnuTrh occultum Stafford, 1905. 



At the close of the discussion on Manodistomwm occultum^ Stafford 

 makes the following statement : " The worms bear many resem- 

 blances to Nr. 86 from the snake of which, indeed, they may be the 

 young." From my experience (outlined above) it seems probable 

 that M. occultum was described from material in its definitive host ; 

 but it is only possible at this time to suggest a probable relationship 

 between the type material and the specimens which Stafford found 

 encysted in the frog. " Nr. 86 " is described in the same paper as 

 Zeugorchis aequatus^ a parasite of the garter snake. Z. aequatus is 

 poorly described, and while it seems to be specifically distinct from 

 M. occultum, I am unable to find valid generic differences. Further- 

 more, if we examine Sumwalt's excellent description of Zeugorchis 

 syntomentera, the only other species referred to the genus Zeugorchis, 

 we are still unable to find generic differences. Therefore Zeugorchis 

 appears to be a synonym of Manodistomwm, and it is possible that 

 the encysted forms from the frog are the young of Z. aequatus. 

 Accordingly Zeugorchis aequatus Stafford, 1905, becomes Manodis- 

 tomum aequatum (Stafford, 1905) ; Zeugorchis syntoinentera Sum- 

 wait, 1926, becomes Manodistomum syntomentera (Sum wait, 1926) ; 

 and Manodistomjuvi occultum Stafford, 1905 {=^Plagitujra salamandra 

 Holl, 1928), stands as the genotype. 



Genus STOMATREMA Guberlet, 1928 



This genus was founded for a single species from the mouth of 

 a snake that had died in the Zoological Gardens of London. As 

 the host had been received from Florida only a fortnight before its 

 death, it is almost certain that the parasites are native to North 

 America. 



STOMATREMA PUSILLA Guberlet, 1928 



My material consists of 24 specimens taken from the esophagus of 

 Farancia ahacura, the trophot3q3e for the parasite. There are a few 

 points in which they differ from this form as described by Guberlet 

 (1928), but the general agreement is so close that very little room 

 is left for doubt as to their specific identity. The only important 

 difference is in the seminal receptacle. Guberlet claims that this 

 structure lies between the posterior borders of the testes and empties 



