236 — THE ANATOMY OF THE COLUMBZ. 
end of this ridge, or into a prolongation of it. In the Columba, 
Psittaci, and Alcide this is not the case; for in them it has quite an 
independent place of insertion into the general surface of the head 
of the bone at some’ distance from the pectoral ridge. An oval 
roughness indicates the spot. It is at the angle formed by the 
pectoral ridge and the main part of the bone in the Galline, but 
nearer the other side of the bone in the Columba. A glance at the 
bone itself or the accompanying drawing of it (fig. 1) will explain 
the point more than any amount of description. It will also be 
Fig. 1. 
Heads of right humerus of :—a. Pterocles arenarius ; b. Gallus bankiva ; 
ce. Columba livia. 
found that the pectoral ridge in the Columbe and some of the Psit- 
taci ends proximally in a point, peculiar to them. The Pteroclide 
agree exactly with the Pigeons in all these points, and differ widely 
from all the Galline. 
In all important features the pelvis of the Pteroclide differs with 
the Columbe from the Galline, as in having no strongly marked 
fossa on the inner surface of the ischium; but in the slight deve- 
lopment of the transverse processes of some of the sacral vertebre it 
is peculiar. 
The general proportions of the muscles in the Pteroclide are per- 
fectly Columbine. The pectoral muscles are similarly disposed, and 
the crop rests on the proximal surface of the great pectoral in a 
similar manner. In the leg the same resemblance maintains. Among 
muscles the ambiens, the femoro-caudal (A), the accessory femoro- 
caudal (B), the semitendinosus (X), and the accessory semitendinosus 
(Y) are all present in Columba and in Gallinw, which prevents any 
difference in myological formula* from assisting in distinguishing 
them. In the obturator internus muscle a well-marked contrast 
* See “ Proceedings of the Zoological Society,” 1874, p. 111. (Supra, p. 208.) 
