ANIMAL PARASITES 5 



Rhabdias bufonis, an European species measuring from 11 to 

 13 mm. has been reported for our native frogs as well. Both 

 species are viviparous and their larvae may be found in the 

 alimentary canal of the frog. 



Pneumonceces sp. — At least six different species of flukes belong- 

 ing to this genus are to be found in the lungs of North American 

 frogs. Mount a specimen and note under the microscope the 

 characteristic suckers. The dark brown eggs, present in enor- 

 mous numbers, obscure most of the anatomical details. The 

 discharged eggs, with a characteristic cap, will be noted later 

 in the intestinal contents. 



Surface of Abdominal Organs. — Lozogenes arcanum is a small 

 trematode living in thick-walled closed cysts on the stomach, 

 liver, and bladder of various frogs. Two individuals occur in 

 each cyst. 



Nematodes. — Several imperfectly known nematodes occur as 

 immature larvae in cysts on the walls of the stomach and various 

 other organs. 



Alimentary Canal. — Beginning at the mouth, slit the alimen- 

 tary canal, examining carefully for various parasites. 



Flukes. — Halipegus occidualis is a moderate-sized fluke with 

 powerful suckers, which is reported from the mouth and Eusta- 

 chian tube of a frog. 



Glypthelmins quieta occurs in the intestine, as does Cepha- 

 logonimus americanus. These two species are small flukes 

 superficially resembling each other very much. They are both 

 cylindrical, cigar-shaped flukes measuring about one-eighth of 

 an inch (3 mm.) in length. A positive differentiation of the 

 species will not be attempted at this time. 



Diplodiscus temperatus, found in the rectum, is recognized by 

 the fact that the enormously developed ventral sucker is at the 

 caudal end of the body. 



Nematodes. — Several species of nematodes may be found in 

 various parts of the alimentary canal. They should be examined, 

 but further study will be postponed. 



Cestodes. — Several species of tapeworms have been reported 

 as adults in the intestines of frogs. Another lives as an encysted 

 larva in the muscles. 



Protozoa. — Numerous Protozoa, representing each of the four 

 classes, are to be found in the alimentary canal and will be 

 studied more in detail at a later practicum. The following 



