528 Bulletin American Museum of Natural History. [Vol. XXXIV, 
But this feature evidently has no diagnostic significance, being merely 
individual. 
Skull. Among the brockets there are long-nosed and short-nosed forms 
both among the red and the brown:species, and while this difference is not a 
group feature, it is characteristic to a certain extent of species and subspecies. 
The amount of variation in this respect can be easily expressed by ratios. 
In the short-nosed species the ratio of the preorbital length (tip of pre- 
maxillaries to front edge of orbit) to the condylobasal length of the skull is 
about 50%, in both red brockets and brown brockets. In other species the 
ratio is sometimes as high as 56%, and such species are also represented in 
both groups. About 53% is the average ratio. (See the Table of compara- 
tive measurements of skulls at the end of this paper.) 
The brockets, like other deer,! present a wide range of individual varia- 
tion in certain cranial characters, especially in those of the preorbital por- 
tion of the skull. The range of individual variation in the size of the skull 
is usually small, as is also the amount of sexual variation in size. In the ~ 
fine series of the brown brocket of the Santa Marta district of northern 
Colombia, the males average slightly larger than the females, but the largest 
skull of the series is that of a female. Five adult male skulls range in total 
length from 180 to 186 mm., five adult female skulls from 175 to 187; condy- 
lobasal length, males 167 to 181, females 167 to 180; occipitonasal length, 
males 155-165, females 155 to 165 mm. The zygomatic breadth in the 
same skulls varies in the males from 77 to 82, in the females from 75 to 79 
mm. ‘The orbital breadth varies in the same series from 3 mm. less to 
4 mm. more than the zygomatic breadth, and the occipital breadth is from 
1 to 4 mm. less than the width of the braincase. 
The nasals, in respect both to relative size and to form, are an exceedingly 
variable element, varying in length from 50 to 58 mm., and in breadth from 
23 to 28 mm., but the long nasals are sometimes narrower than some of the 
short ones. They vary in outline on the posterior border from slightly to 
deeply emarginate; on the front or apical border from obtusely rounded 
(about 40% of the series) to doubly emarginate (about 40%), in which the 
central (inner) points extend much beyond the outer, or all four points may 
be of nearly equal length, giving a symmetrically double-emarginate front 
border; in others (about 20%) the anterior border is variously intermediate 
in form between these two strongly contrasting outlines. 
The varying subbasal width of the nasals greatly modifies the size and 
form of the antorbital vacuity, which is twice larger in some specimens than 
1 See exposition of the case of Odocoileus sinaloe, described and illustrated in this Bulletin, 
Vol. XXIT, pp. 203-208, pll. xxiil—xxiv, July 25,1906. — 
