C. L. Boulenger 
245 
the posterior narrow region is not straight but follows a somewhat 
sinuous course (PL XIX, fig. 4). 
Females. The two female individuals measure 7-5 and 6-3 mm. 
in length; the smaller specimen is immature and the measurements 
given below are taken chiefly from the larger one. 
The body is thickest in the region of the vulva where it has a width 
of 100 p,, the diameter at the base of the oesophagus is 62 p,, at the anus 
40 jU. 
The longitudinal ridges of the cuticle show up clearly and have 
the finely beaded appearance noticed by Ransom in the type specimens. 
The oesophagus measures 500 p. in length with a maximum breadth 
of 40 p posteriorly. 
The anus is aboixt 110 p from the tip of the tail, the latter being 
slender and gradually attenuated, ending in a rounded tip, devoid of 
the annular striations so characteristic of Osteriagia circumcincta. 
The vulva is a transverse, naked slit, situated 1-15 mm. from the 
posterior end of the body, it is not protected by a projecting flap of 
cuticle. 
The muscular portions of the ovijectofs have a length of 300 p, 
ncluding the sphincters. 
The eggs in the uterus measure 85-95 p long by 40-48 p wide, they 
are very similar to those of 0. circumcincta. 
7. Cooperia oncophora Raiilict. 
[Strongylus ventricosus Rudolph! [in part].) 
A number of specimens of this worm were obtained on one occasion 
from the small intestine of a sheep received from the Birmingham 
abattoirs. 
C. oncophora has been found in cattle and sheep in the United 
States, and in cattle in different parts of Europe; this is I believe the 
first record of its occurrence in sheep in England. 
The specimens collected in Birmingham agree in every respect with 
those described by Ransom in his monograph. The males measure 
6-8-8 mm. in length by 250-300 p in width in the thickened region 
at the base of the bursa. The spicules are 270-300 p long and are of 
simple structure. The arrangement of the bursal rays is shown in Fig. 2. 
The females have a length of 8-8-5 mm., the body is thickest in the 
region of the vulva, where the cuticle is much dilated. The vulva is 
a transverse slit, with prominent lips, situated about 2 mm. from the 
