124 PARASITOLOGY. 
tines. In making a collection of the strongylus for 
study I find that while the majority of worms are 
found close to the mucous membrane or between the 
fecal matter and mucous membrane yet some are in- 
corporated in the mass of partially digested material. 
The following species of this genus cylichnosto~ 
mum have been studied in this laboratory: tetracan- 
thum, labratum, labiatum, bicoronatum, poculatum, 
calicatum, alveolatum, catinatum, nassatum, radiatum, 
and elongatum. 
Cylichnostomum tetracanthum.—Length of male 9 
mm. (one-third of an inch), thickness .25 mm, fe- 
male up to 12 mm. (one-half inch) long, thickness .5 
mm. Lateral head papillae not prominent, subme- 
dian head papilla moderately long. Esophagus short 
and stout. See figures 31, 32 and 33, Plate 11. 
Cylichnostomum labratum.—Body slender. Length 
of male up to 8 mm., female 9 mm. Maximum thick- 
ness of male, .25 mm., female 33 mm. Head 
separated from the body by a slight construction. 
Papillae same as in C. tetracanthum. See figures 45, 
46 and 47, Plate 11. 
Cylichnostomum labiatum.—Length of male up to 
9 mm., female 11 mm. Thickness of male up to .33 
mm. and female 42 mm. See figures 27, 28, 29 and 
30, Plate 10. 
Cylichnostomum Gein Rte stout and 
