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ILLINOIS BIOLOGICAL MONOGRAPHS 



[412 



Type specimen: No. 174.2 of the writer's collection. 

 Co-type: No. 174.3 of the same collection, deposited in the collection of the 

 University of Illinois. 



Type locality : Georgian Bay, Lake Huron, off Giant's Tomb Island. 



So far as the writer has been able to ascertain a description df this species 

 has not yet been published, nor have any bothriocephalid cestodes been reported 

 for Stizostedion vitreum (Mitchill), the common pickerel or wall-eyed pike. 



In general appearance this species does not arrest attention imtil a fairly 

 close examination is made, since it is comparatively small and when much 

 relaxed not so very different, at least posteriorly, from some of the species of 

 Proteocephalus, one of which evidently not yet reported, was found associated 

 with it in the same host. It is medium sized, attaining a length of about 180 

 mm. with a maximum breadth of about 2.75mm. 



The scolex, on account of its comparatively great depth, is more often seen 

 and much more conspicuous from a lateral view (Fig. 25). Dorsoventrally 

 (Fig. 24) it is long and narrow, showing a terminal disc well set off from the 

 bothria, while laterally it is roughly shaped like an arrow-head, as indicated 

 by the specific name chosen, or somewhat comparable to a flask or vase pro- 

 vided with a low conical lid (the terminal disc). The bothria are long, narrow 



