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. 



Sclcrostomum 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 one-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. Th-e teeth have rounded termina- 

 tions. See figures 1 and -i, 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 in 

 the floor of the oral capsule. These teeth are direct- 



