1915.] | Allen, American Deer of the Genus Mazama. 527 
thicker and much longer, this reversal of the nape hairs is apparently always 
absent. Nor has it been noted in several other species of the red group. 
In a large series of the brown brocket of Santa Marta none have the nape 
hairs reversed, nor are they reversed in any other species of the brown 
group, so far as my limited material (about 20 specimens) gives evidence. 
Antlers. ‘The antlers, normally a single tapering spike, vary greatly in 
development even in adult males of the same species, and are so nearly 
alike in size and general character in both the red and brown species that 
they are not diagnostic. They vary in length (measured from the burr) 
in fully adult males from the same locality (e. g., Santa Marta) from two to 
nearly five inches (55 to 115 mm.). The longest pair of antlers belongs to 
the single specimen from Paraguay (135 mm.); both species are members of 
the brown group. In both groups there is a marked tendency to malforma- 
tions, through the broadening of the burr and basal portion of the antler, 
the shortening of the shaft, and the development of large accessory tubercles 
at the base. The exterior of the shaft is subject to great variation, being 
in some cases smooth and polished and nearly circular in crosssection, in 
others roughened with sharp ridges and more or less triangular in cross- 
section. , 
Teeth. G. Cuvier,! in discussing the characters of supposed species, 
laid great stress on the presence or absence of canines in the upper jaw, and 
in this he was followed by various subsequent authors. Later Pucheran? 
reached the conclusion that they were evanescent, being usually present in 
young animals and absent in adults. Brooke,® in his diagnosis of the 
subgenus Coassus (= Mazama) stated: “Canines of uncertain occurrence.” 
My material (more than 60 skulls) confirms Pucheran’s opinion that they 
are essentially a feature of the milk dentition, they being rarely present in 
skulls of mature animals. I have found only three instances of their pres- 
ence in some 50 adult skulls, in two of which only one canine was present 
in each, in the other both. In young skulls with milk dentition in tact, both 
canines are usually present in both sexes; they usually disappear during the 
development of the molars, but the alveoli remain more or less distinct till 
the permanent dentition is fully developed, and sometimes they can be 
plainly seen in adult skulls. 
The molars usually show no trace of a supplementary column (on the 
inside of the upper and on the outside of the lower); there is frequently a 
vestige on one or more of the teeth, and very rarely a strong column on each 
molar, which forms part of the enamel pattern as the teeth become worn. | 
1 Ossem. foss., 2d ed., IV, 1823, p. 53-55. 
2 Arch. du Mus. d’Hist. nat. Paris, VI, 1852, p. 480. 
3 Proc. Zool. Soc. London, 1878, p. 924. 
