204 



EDWIN LINTON. 



August 29, 36 snails examined in the usual way. No sporo- 

 cysts were found. 



The following notes were made on material that had been 

 stained and mounted in balsam. 



The shape of the cercariae varies greatly but seems to be due to 



Fig. 6. Cercaria from Ilyanassa obsoleta, in balsam. Length 0.30 milli- 

 meter, exv, excretory vessel; m, oral sucker; oe, esophagus; p, piepharynx; pk, 

 pharynx; t, testes; v, ventral sucker. 



different methods of fixing, or, at least to different degrees of con- 

 traction. When fixed under pressure they are more or less 



