158 MR. W. K. PARKER ON THE OSTEOLOGY 



development in the " Tetraonidse," and are enormous in the Cock of the Woods {Tetrao 

 urogallus). These angular processes are similarly developed in the "Anatinse." 



I have not been able to find a " coronoid " element as a distinct piece in the chick, 

 although we see it in the Ostriches, and indeed in most birds. The os hyoides is very 

 elegant in all these " Gallinae ;" the true hyoid cornua are delicate and He in the tongue, 

 their tips being cartilaginous ; there is also a basi-hyal, a uro-hyal, and the two double 

 thyro-hyals : all delicate and rather feebly ossified (PI. XXXVI. fig. 10). 



Lastly, the great anterior semicircular canals are a considerable distance from each 

 other over the sides of the foramen magnum ; and yet the posterior crus of each canal 

 is imbedded in the side of the corresponding superoccipital. There is no distinct 

 " epiotic " in the chick ; but on about the eighteenth day of incubation a small 

 " opisthotic " may be seen: it soon coalesces with the exoccipital. In Lagopus the 

 columella is extremely delicate, the rod being fine, and the basal plate large and thin ; 

 the rod thickens before it trifurcates, but the branches do not ossify. I have never 

 seen in these, nor indeed in any other birds, any bone answering to the os orbiculare 

 of Man and the superquadrate ossicle of the Lizard ; nor does there appear to be any 

 bone in birds answering to that small osseous segment of the periotic capsule of the 

 Mammal which becomes converted into the " pyramid," and which appears to be a 

 rudiment of that huge proximal piece of the hyoid arch of the fish, which, breaking 

 away from the postfrontal, ali-temporal, and prootic regions, becomes developed into 

 the hyo-mandibular. With regard to the structure of the rest of the skeleton of the 

 type and subtype, it may be remarked that the differences are similar to what is 

 seen in the skull. On one hand, we have coarseness of texture, with a considerable 

 amount of diploe ; on the other, there is a lathy and rather tough than strong condition 

 of the bones. In treating of the other groups of Gallinse, I shall have to speak of the 

 skeleton both of the Fowl and of the Grouse. It may be said, however, that the 

 sternum of the typical Fowl and Pheasant is exactly intermediate between that of the 

 gigantic Turkey and Peacock, on one hand, and that of the Quail and Partridge 

 (PI. XLI. figs. 9 & 10) on the other, and that in the gigantic forms the shortness of the 

 hyposternal processes and the general characters of the entire bone closely approxi- 

 mate to the conditions we find in the Brush-Turkey {Talegalla), and the Curassow (Crax). 

 There is, however, one of the typical species, a dwarfish form, of which I must speak 

 before passing on to the Megapods ■ this is the Guatemala Tree-Partridge (Dendrortyx). 

 Larger than the true " Quails," yet possessing the same general osteological characters, 

 the Dendrortyx may be said to have in its skull and face the Quail-characters highly 

 exaggerated. The occipital plane is vertical and flat, the condyle bifid, the tympanic 

 cavity shallow, the skuU-wails thick and having a rather coarse diploe, the interorbital 

 septum somewhat deficient, the bird being rather small ; the temporal space is bridged 

 over, as usual. The antorbitals and the rest of the lateral ethmoidal and pre-ethmoidal 

 structures continue cartilaginous as in the type. The vomer and the palatines are as 



