OSTEOLOGY OF BIRDS 175 



the anterior processes of a nasal bone only partially anchylose with 

 the premaxillary above, and below, and with care these latter bones 

 can be easily detached along their sutural lines. A nasal bone is 

 separated from its fellow of the opposite side by the median, back- 

 ward-extending process of the premaxillary, as is the case in most 

 of the domestic species. However, Darwin calls attention to the 

 fact that in the " Sultans" (a Turkish breed), the inner processes 

 of the nasal bones were ossified together. 1 



A lacrymal in G . b a n k i v a is a small scalelike bone, sub- 

 triangular in outline, and freely articulated along its inner border 

 to the anterior nasofrontal margin of the orbit. From its apex in 

 front there descends a delicate and semispiral spine, twisted from 

 within outward, that in the prepared skull reaches about half way 

 down to the quadratojugal bar. 



These lacrymal bones are much alike in a great many species of 

 gallinaceous birds, and I found them in all our American grouse 

 much as they exist in these wild chickens of India 2 now under con- 

 sideration [sec fig. 2, 3, 4]. 



Viewed as a whole, the superior aspect of the skull in both cock 

 and hen G. bankiva is smooth, and presents for examination 

 a pair of domelike eminences posterior to the orbits and formed 

 by the frontal bones, while the interorbital area is broad and quite 

 flat. Longitudinally in the median line, from parietal region to the 

 shallow excavation between the lacrymals there runs a faintly 

 marked groove, most evident in the male bird, which is less pro-' 

 nounced in front than it is posteriorly. In this groove in the male, 

 and beneath the site of the comb, there is to be found a fairly well 

 marked elevation [fig. 3], of which there is not a trace in the hen. 

 Then again, a pair of inconspicuous and elongated elevations, one 

 occurring on either side of the median furrow, are to be observed 

 immediately in front of the transverse frontoparietal depression, 

 in which elevations the bone of the cranial vault appears to be 

 thinner, as may be seen by holding the skull up to the light. The 

 parietal region of this superior aspect of the cranium is broad, con- 

 cave from side to side, gently sloping down on either hand to the 

 tympanic apertures, where the squamosal completes the cranial 

 surface. 



1 Ibid, p. 320. 



2 ShufeMt, R. W. Osteology of the North American Tetraonidae. U. S. Geol. St 

 Geoer. Sur. Terr. Hayden's 12th An. Rcp't. pi. 10, 13, fig. 71, 73, 88. Sg. Author's 

 edition published separately, entitled Contributions to the Anatomy of Birds, Washing- 

 ton, Oct. 1882. 



