42 PROCEEDINGS OF THE NATIONAL MUSEUM vol.81 



crepancies that Joyeux noted are so great that specific identity seems 

 very unlikely, particularly since a form discovered from an Ameri' 

 can reptile appears so similar. 



Genus CYSTICERCUS Rudolphi, 1809 



CYSTICERCUS sp. 



Plate 4, Figures 2, 3 



A larval cestode was encountered three times, twice in Leiolopisma 

 laterale and once in Emneces fasciatus. It was found lying free in 

 the body cavity or entangled in the mesenteries ; in all three cases it 

 was present in great abundance. The cyst is a white globular struc- 

 ture about 0.6 mm in diameter and exhibits very little movement 

 when removed to a dish of water. The unarmed scolex lies entirely 

 free within the cyst wall. This type of larval form corresponds to 

 the group of cysticercoids which Villot (1883) designated by the 

 name Monocercus. The known members of this group include the 

 larval forms of certain species of Anomotaenia. The unarmed 

 scolex and the occurrence of the cysts in lizards suggest the possibil- 

 ity of this form being the larval stage of an Oochoinstica. 



Class NEMATODA 



Family RHABDIASIDAE Railliet, 1915 



This family is not recognized by Baylis and Daubney (1926), 

 but it seems to the author that its peculiar life history and the 

 structure of the parasitic form justify the recognition of a family 

 for this group of worms. 



Genus RHABDIAS Dujardin, 1845 



The presence of members of this genus in the lungs of the North 

 American frog has long been known, but until recently they were 

 regarded as specifically identical with R. hufonis of European 

 Amphibia. Two other species of Rhabdias have recently been de- 

 scribed from South America, which bring to three the total number 

 of species from the Americas. Two of these three species were found 

 locally. 



RHABDIAS RANAE Walton, 1929 



This parasite has been found in the lungs of Rana catesheiana 

 and R. sphenocephala, which were captured in the region of Hous- 

 ton, Tex., and from the former host at Huntsville, Tex. 



