208 Proceedings of Indiana Academy of Science 



specimen is much shrunken and fore-shortened. These forms occurred 

 chiefly in the connective tissues of the host, but could be found generally 

 throughout the body, as in the lungs, the digestive tract, the body cavity, 

 and in the liver and spleen. In these last their presence was indicated 

 by gray, granular, necrotic patches upon the surfaces. On several oc- 

 casions these Distomes were observed in the web of a frog's foot, where 

 they seemingly had no difficulty in making their way, moving rapidly 

 across the field of the microscope. 



The extent to which these Distomes are true parasites of the forms 

 they infest is problematical. In all cases where this infestation oc- 

 curred an excessive number of free-living Distomes were also found in 

 the tissues of the frog. In neither the Cestode nor Clinostomes were 

 these secondary parasites encysted, a fact which would suggest a for- 

 tuitous occurrence. It seems altogether probable that in their extensive 

 migrations these small forms could accidentally force their way into other 

 parasites, especially if the body substance of these offered less resist- 

 ance than did the tissues of the primary host. These secondary para- 

 sites varied considerably in size, but were of the same general appear- 

 ance. Because of their immature condition no exact identification is 

 attempted. In their gross anatomy they agree closely with Agntuodis- 

 iomiuti niaycianae,' a cercaria described by Cort as follows: "The ven- 

 tral surface is completely covered with spines which are very thickly 

 set over the anterior tip and .somewhat scattered in the post-acetabular 

 region. The margin of the acetabulum is armed with two or three rows 

 of closely set spines pointing in, which are so placed that they add 

 greatly to the gripping power of the sucker. The host in which Aga- 

 modistomnm murcianae complete its development is not known. Also 

 its structure at this stage gives little clue to the systematic position of 

 the adult. The character of its cephalic glands and excretory system, 

 however indicates that it has developed from a forked-tailed cercaria." 



' Coi-t, W. W. The Excretory System Of AKamodistomum Marcianac (La Rue), The 

 AKamodistomo .Staiic Of A Korked-Tailecl Cercaria. Jour. Parasit.. 4 l:!0-l.'!4. ."J figs. 

 1918. 



