TREMATODE SPOROCYSTS AND CERCARI^. 



203 



August 24, 24 snails were removed from their shells, picked to 

 pieces with forceps, washed, the water decanted, and about 10 

 sporocysts found. These were linear oblong, frequently arcuate 

 and slipper shaped, thickish. Dimensions in millimeters: 



Length 0.66 



Breadth 0.25 



Fig. 5. Cercaria from Tlyajiassa ohsoleta, stained and mounted in balsam, dorsal 

 view, showing oral spine, rudiments of prepharynx, pharynx, testes, etc. Length 

 0.30 millimeter. 



August 26, 24 snails were examined that had been opened and 

 removed from their shells the day before. No sporocysts were 

 found. Another lot of 24 were opened and examined on this 

 date. No sporocysts were found. 



