198 THE MYOLOGY OF THE RAVEN. 



Referring to the myology of Geococcyx calif ornianus 

 and the four last muscles we have just been considering, 

 we find that the obturator internus arises from an oval 

 area, and has much the same origin and insertion as 

 we find it here in the Raven. In Geococcyx, too, the 

 yemellus (Fig. 65 bis) is a short, thick, carneous muscle, 

 which arises about the outer rim of the obturator foramen 

 of the pelvis. Its fibres passing obliquely upwards and 

 forwards are inserted with the tendon of the obturator 

 internus muscle on the trochanter of the femur. This 

 bird also has a few of the fibres of its gemellus muscle 

 inserted into the tendon of the obturator externas muscle, 



" is a somewhat short thick muscle, of a parallelogrammic form, 

 fleshy throughout ; rising from the tuberosity of the innominatuui 

 in front of the acetabulum immediately below the glutens minimus, 

 and inserted at a point corresponding to the inner trochanter, into 

 the inner side of the femur near the head of that bone, which it 

 thus adducts and rotates outwards. This muscle is present both in 

 the Ostrich and Bustard. 



" The pyramidalis arises fleshy from the outer surface of the 

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

 tendon, which is inserted into the trochanter femor is, opposite, but 

 close to, the tendon of the gluteus minimus, which it opposes, ab- 

 ducting and rotating the femur outwards. 



" The adductor brevis femoris arises from the innorninatum 

 immediately behind the acetabulum, passes over the back part of 

 the great trochanter, becomes partially tendinous, and is inserted 

 into the back part of the femur. 



"The quadratus is 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 " (Anat. of Verts., vol. ii. pp. 100-102). 



Since writing the above notes, I have gone more fully into the 

 literature of the myology of birds, made possible by better- 

 facilities, and it will be evident from the synonymy I have added 

 from Gadow throughout this work what some of these muscles of 

 Owen's are ; as, for instance, the pyramidalis is evidently my 

 obturator externus ; or No. 40 of Gadow, his m. ischio-feinordlis, 

 R. W. S. (June 25, 1889). 



