74 CONTRIBUTIONS TO AMERICAN HELMINTHOLOGY. 
ANCYRACANTHUS SERRATUS, %. sp. 
A single female specimen of a worm closely allied to the above 
was obtained from the auricle of the heart of Coregonus albus, Le 8. 
It only measures 11 mm., and differs from A. cystidicola in the mouth- 
armature. Instead of having only the two teeth of that species, there 
are a series of smaller ones disposed, as represented in Fig. 18, round 
the anterior end. The eggs in this specimen were not mature, but 
the genital organs were observed to be arranged as in the above 
species. The structure of the cesophagus is sufficient to place the 
worm in this genus, and I propose provisionally for it the specific 
name “serratus.” 
Toronto, December, 1878. 
