PARASITOLOGY. 121 
This genus has three species, viz: equinum, eden- 
tatum, and vulgare. They are usually found in the 
cecum and first portion of the large colon. 
Sclerostomum equinum.—(Strongylus armatus. 
Strongylus neglectus). This is the largest species of 
strongylus found in the intestines of the horse. The 
male measures up to 35 mm. (one and cne-half 
inches) long and an average thickness of 1.25 mm. 
while the female measures up to 47 mm. (nearly two 
inches) long and 2.25 mm. in thickness. See figures 
2 and 3, Plate 9. Three teeth are found within the 
mouth ‘capsule. The teeth have rounded termina- 
tions. See figures 1 and 4, Plate 9. 
Sclerostomum edentatum.—Sclerostomum  equin- 
um). This is the next largest species of strongylus 
under consideration. The male measures up to 26 
mm. (one inch) long and 1.5 mm. thick. The female 
up to 36 mm. (one and one-half inches) long and 2 
mm. in thickness. The head is distinctly divided 
from the body. The mouth is cup-like in shape and 
there are no teeth-like projections. See figure 6, 
Plate 9, and figure 9, Plate 9. 
Sclerostomum vulgare.—(Sclerostomum armatum). 
The male measures up to 16 mm. (two-thirds of an 
inch) long and diameter about .75 mm. while the fe- 
male measures up to 24 mm. (one inch) in length 
and 1 mm. in diameter. The mouth is slightly cup- 
shaped with the dorsal aspect more convex than the 
ventral. See figures 14 and 19, Plate 10. 
GENUS ‘TRIODONTOPHORUS. 
This genus is provided with three teeth located 11 
the floor of the oral capsule. These teeth are direct- 
