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 memhrane or between the 

 fecal matter and mucous membrane yet some are in- 

 corporated in the m^ass of partially digested material. 

 The following species of this genus cylichnoisto- 

 mum have been studied in this laboratory: tetracan- 

 thum, labratum, labiatum, bicoronatum, poculatum, 

 calicatum, alveolatum, catinatum, nassatum, radiatunt 

 and elongatum. 



Cylichnostomitm 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. 



Cylichnostomumr bicoronatum. — Body stout and 



