PARASITOLOGY. 123 
cussed the following genera: Cylichnostomum and 
Gyalocephalus. 
Synonyms for this group are: Sclerostomum 
tetracanthum and Strongylus tetracanthus. 
GENusS CYLICHNOSTOMUM, 
The cylichnostomum was so named from the re- 
semblance of its mouth parts to a small cup, which 
the word means. 
The general form of the body is stout. The tail 
of the female is slender and pointed. The body has 
transverse markings in the skin. The male is pro- 
vided with a caudal pouch which possesses two spicu- 
lae of equal size and shape. The intestine runs 
straight through the body and is usually visible to the 
naked eye especially after clarification of the speci- 
men. Looss has apparently proven that the function 
of the spiculae is one of copulation as he has observed, 
in at least one case, the spiculae introduced into the 
inner genitals of the female in a copulating pair. He 
has also observed that the food of the cylichnostomes 
is a colorless crumbly more or less coarsely granular 
substance including to a varying extent particles of 
all kinds of vegetable debris, pieces of straw, starch 
granules and often ova and infusoria. Thus it will 
be seen, that from a study of the intestinal contents 
there may be some doubt as to whether they are true 
blood suckers. The writer in his study of more than 
300 specimens has noted in one case the ingestion of 
two ova. 
These worms pass through their larval stage in 
cysts in the mucous membrane of the large intes- 
