1888.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 421 



Brooke's diagnoses by which the species may be distinguished from 

 those of Cariacus. The small amount of material which I have been 

 able to examine seems to warrant such a disposition of them. Coassus 

 on the other hand, presents many characters which distinguish it from 

 Cariacus. In Brooke's valuable diagnoses four differential characters 

 may be found. These are as follows: In Coassus {a) the auditory bullae 

 are less inflated than in Cariacus; (b) the rhiuarium is ample, as in 

 Crevulus; (c) the facial profile is more arched than in Cariacus; and 

 (d) the stature is small. In the first three of these characters our new 

 species agrees with Cariacus rather than with Coassus. The fourth 

 character, relating to stature, is perhaps scarcely worthy of considera- 

 tion as a subgeneric distinction; it is a matter apparently correlated 

 with the small size of the antlers. To bring together our new deer and 

 the various species of Coassus, on account of their small size, would nor 

 be more logical than to approximate two large species merely on the 

 score of their common magnitude. 



Leaving size out of consideration, therefore, C. clavatus, judged by 

 the diagnoses of Sir Victor Brooke, belongs in the subgenus Cariacus. 

 I now desire to bring forward three additional characters which our 

 new deer possesses in common with the known species of the subgenus 

 Cariacus and which separate it from Coassus. 



It is pointed out by Brooke that in the deer of the New World the 

 vomer extends backward in the nasal cavity, dividing it into two com- 

 pletely separated compartments. Upon examining the vomer in the 

 different species of the subgenus Cariacus, C. virginianus, macrotis, etc., 

 I find that the posterior end of the superior horizontal plate, while it 

 covers the prespheuoid, does not extend over the suture between the 

 prespheuoid and the basisphenoid. The free posterior margin of verti- 

 cal plate is falcate, and in old individuals the attenuated extremity of 

 the same curves backward and touches, or actually grows into, the sur- 

 face of the basispheuoid. In Coassus, on the contrary, the horizontal 

 plate of the vomer extends back far enough to cover the suture be- 

 tween the prespheuoid and basisphenoid, and the free posterior margin 

 of the vertical plate is straight or only moderately eaiargiuate. In C. 

 clavatus the form of the vomer is that of Cariacus, and not of Coassus. 



As a second distinguishing character, I find that in all the species of 

 the subgenus Cariacus the osseous walls of the external auditory 

 meatus are incomplete in the center behind, thus Q, while in Coassus 

 the vacuity occurs much higher up, thus Q. In this, as in the last 

 character, C. clavatus shows a relationship to species of the subgenus 

 Cariacus. 



The third character to which I shall call attention relates to the ar- 

 rangement of the hair on the face. The matter of the arrangement of 

 the hair, as Sir Richard Owen has somewhere stated, deserves more at- 

 tention than it has thus far received. So far as my observations go, the 

 s'yleof arrangement is very constant in individuals of the same species, 

 or in the species of a group. In all the Cats, for example, the hair on 



