8 VETERINARY OBSTETRICS. 
which the sacro-sciatic ligament is fixed. Below the 
cavity, and inclining inwards, is a large circular open- 
ing, occupied by the obturator muscles and known as 
the foramen ovale, or obturator foramen. The two 
ossa tnnominata are united in the middle line inferiorly 
and posteriorly by a solid suture—the symphyszs 
pubis, or ischio-pubic symphysis. Above they articulate 
with the sacrum. 
Fic. 1. 
PELVIS OF THE MARE. 
A, Ilium; B, Pubis; C, Ischium; D, Foramen Ovale; E, TBE of the 
Ischium; F, Cotyloid Cavity. 
The os cnnominatum is composed of three portions 
uniting at the acetabulum, and have received the names: 
the zlzum, tschium, and pubs. 
The zlium, hip, or haunch, is the largest of the three 
bones. It is irregularly triangular in shape, and is 
directed obliquely downwards, inwards and backwards, 
and has two faces, three borders, and three angles, 
The external face presents the external iliac fossa; 
the internal face the iliac surface, and an auricular 
