OF GALLINACEOUS BIRDS AND TINAMOUS. 157 
In the ‘‘ Tetraonine’ the antorbitals, however, are multiplied, and ossify. In Tetrao 
cupido there are three, and in T. wrogallus four cartilaginous pieces behind the middle 
turbinal, instead of a continuous pars plana, as in the Mammals and Ostriches ; these 
antorbitals are ossified. The middle ethmoid becomes very thick in Tetrao urogallus. 
The orbito-sphenoidal region is but little indebted to the true orbital ale in Galline ; 
and these ale are ossified continuously from the presphenoid, which is sometimes com- 
posed of two pieces, as in Pavo. The orbital plates of the frontal wall-in the membra- 
nous skull at this part, and supply the deficiencies of the true orbito-sphenoids. 
Tetrao urogallus has small free orbito-sphenoids when examined during the first 
summer. In neither the Fowl nor the Grouse is there any very definite outgrowth of 
the ali-sphenoid answering to the ‘‘external pterygoid plate.” In both these groups 
the lachrymal has a strong superorbital plate ; but the descending process is very feeble 
and styloid, most so in Lagopus and Tetrao. The nasals in both type and subtype are 
lath-like, broad, ascend only a moderate way up the frontal region, and have rather 
short anterior processes ; the outline between these processes, an upper and a lower, 
is gently concave, more so than in the ‘‘ Anatine.” The premaxillary is strong and 
arched, and descending ; the dentary margin very sharp, and the palatine process a 
mere splint. There is no maxillary ; and the prevomerine bones are very small in the 
type, still smaller in the subtype. They are composed each of a flat scale-like body, 
a slight ascending process (the rudiment of the shell-like outer portion of the bone in 
the Ophidian and Lacertian), an inner process (feeble and flat in the Fowl, still feebler 
in the Grouse), and a posterior or zygomatic process. 
This latter process is vicarious of the zygomatic process of the lost maxillary (which 
exists as a mere rudiment in a few birds, as the Emeu, Night-Heron, Egret, and Swift’) ; 
and it overlaps the feeble malar style, which in its turn overlaps the equally feeble 
quadrato-jugal. The vomer is in both groups a feeble style, bifurcate at the posterior 
end ; it is double in Numida meleagris, one of the types, and broad in the subtypical 
Tetrao urogallus. The feeble palatines are just a step above those of the ‘‘ Stru- 
thionide ;” they have the long anterior, very ornithic splint. The pterygoids are 
thick, and in both kinds articulate by a double head with the os quadratum. In a 
chick nearly a week old I have found a small distinct ‘‘ meso-pterygoid ” between the 
head of the pterygoid and the rostrum of the basi-sphenoid. The mandible in both 
kinds is very strong: in the type the membranous space becomes filled up ; it is very 
large and oval in the ‘‘ Tetraonide.’”’ The external and internal angular processes (the 
latter the homologue of the Mammalian manubrium mallei) are long in the type, the 
internal being strong, the external sickle-shaped and flat. These parts have a similar 
1 There is a rudiment also of this bone in the small Egyptian Glede (Zlanus melanopterus) ; and in the Great 
Penguin (Aptenodytes antarctica) (Osteol. Catal. Mus. Coll. Surg. vol. i. p. 216, no. 1118) there is a splint- 
like, delicate maxillary, 3 inches in length. 
