4 PROCEEDINGS OF THE NATIONAL MUSEUM voi . s2 



three distinct lips. In species of the genus Ostertagia, examined by, 

 the writers, the Hps are indistinct, as shown in Figure 2, which repre- 

 sents en face views of the heads of Ostertagia ostertagi, 0. marshalli, 

 and 0. circumcincta. 



Male, 4lA mm to 5.5 mm long by 80m to 85^ in maximum width. 

 The head is about 16/Lt in diameter. The esophagus is club-shaped, 

 about 452ju to 490^ long. The nerve ring divides the esophagus into 

 two parts, that anterior to it being approximately one-half as long as 

 that posterior to it. The excretory pore is about 205^ to 235^ from 

 the anterior extremity of the body (fig. l,h). The bursa is about 365/u 

 wide when spread out. The ventro- ventral and latero-ventral rays 

 are of approximately ec^ual diameter and widely separated; both rays 

 reach the margin of the bursa, the former being in relation with a con- 

 spicuous prominence of the margin of the bursa. The tip of the ex- 

 terno-lateral ray does not extend to the margin of the bursa; the ti])s 

 of the medio-lateral and postero-lateral rays are in contact with the 

 margin of the bursa. The externo-dorsals arise from the dorsal. The 

 latter divides distally and gives off a slender lateral branch on each 

 side, immediately in front of the two terminal branches; the latter 

 are forked at their posterior extremities. The accessory bursa is 

 supported by two slender rays (fig. 1, d). The spicules are slightly 

 dissimilar in length and are also morphologically distinct; the right 

 spicule is 112/i to 121/x long and is provided with a single very slender 

 inner process; the left spicule is 11 "^ to 125/1 long and contains two 

 inner processes, a large one originating at a point anterior to the 

 middle of the spicule and a very small slender one corresponding to 

 that of the right spicule (fig. 1, ^). The gubernaculum is 62/i to 72^ 

 long by 7/i in maxinuim width (fig. I, e). 



Female, 4.6 mm to 5.8 mm long by 83m to 109^ in maximum width. 

 The head is about 20m in diameter. The esophagus is 468m to 5 10m 

 long. The excretory pore is 195m to 240m ^^nd the nerve ring 144m to 

 180m from the cephalic extremity (fig. 1, c). The vulva is approxi- 

 mately 1 mm to 1.2 mm from the posterior extremity of the bod}'. 

 The entire ovejector apparatus, including the sphincters, is somewhat 

 less than 500m long (fig. 1, /(). The anus is located at a distance of 

 90m to 115m from the posterior extremity. The terminal portion of the 

 tail is bent ventral, the tip being bluntl}'^ rounded (fig. 1,/). The 

 eggs are 60m to 72m long by 24m to 26m wide (fig. I, g). 



Host. — Pecari angulatus angulatus (Cope). 



Location. — Small intestine. 



Locality. — Vicinity of Raymond ville, Tex. 



T^/^pe s^ecme/zs (male and female). — U.S.N.M. Helm. Coll. No. 

 30165. 



P«m/?/pes.— U.S.N.M. Helm Coll. No. 30166. 



