226 Zoological Society. 



bone, which it thus adducts and rotates outwards. This muscle is 

 present both in the Ostrich and Bustard, but Meckel says it is want- 

 ing in the Cassowary. — Arch. xiii. 261. 



Pyramidalis. — The same kind of modification which affects the 

 iliacus internus, viz. the displacement of its origin from the inner 

 surface of the ilium to a situation nearly external, affects this muscle, 

 which, from its insertion and triangular form, I regard as the ana- 

 logue of the pyramidalis. It arises fleshy from the outer surface of 

 the extended ischium for the extent of an inch, and converges to a 

 broad flat tendon which is inserted into the trochanter femoris oppo- 

 site, but close to, that of the gluteus minimus, which it opposes, ab- 

 ducting and rotating the femur outwards. 



Adductor brevis femoris. — A small, long and slender muscle arises 

 from the innominatum immediately behind the acetabulum, passes 

 over the back part of the great trochanter, becomes partially tendi- 

 nous, and is inserted into, the back part of the femur in common with 

 the following muscle. 



Adductor longus. — A long broad and thin muscle, separated from 

 the preceding by the ischiadic nerve and artery. The origin of this 

 muscle extends one inch and a quarter from near the upper margin 

 of the innominatum which is behind the acetabulum ; it is joined by 

 the preceding strip, and is inserted into the whole of the lower two- 

 thirds of the back part of the femur. 



Adductor magnus. — This broad and flat muscle has an extensive 

 origin (two inches) from the outer edge of the ischium and the 

 obturator fascia ; its fibres slightly diverge as they pass downwards 

 to be inserted into the back part of the lower half of the femur, and 

 into the upper and back part of the tibia. 



Obturator internus. — This arises from the inner side of the oppo- 

 site margins of the pubis and ischium, where they form the posterior 

 boundary of the obturator foramen, and from the corresponding part 

 of the obturator fascia ; the fleshy fibres converge in a slightly pen- 

 niform manner to the strong round tendon which glides through the 

 notch, separated from the rest of the foramen by a short, strong, trans- 

 verse, unossified ligament, and is inserted into the posterior part of the 

 base of the trochanter. In its length and size this muscle resembles 

 the corresponding one in the Ostrich and other Struthious birds. 



Gemellus. — This is represented by a single small fleshy strip 

 arising from the margin of the obturator foramen, close to the emer- 

 gence of the tendon of the obturator internus, with which it is joined, 

 and co-inserted into the femur. 



Quadratus. — I consider a broad fleshy muscle which arises from 

 the pubis, below the obturator foramen, and which increases in breadth 

 to be inserted into the femur internal and posterior to the obturator 

 tendon, to be the true analogue of the quadratus femoris. 



Muscles of the Leg. 



Tensor vagina and Rectus femoris. — The largest and most remark- 

 able of the muscles which act upon the bones of the leg is that 

 already alluded to as the most superficial of those on the outer 

 side of the thigh. It has a broad, thin, triangular form, arises from 



