92 
OSTEOLOGICAL GALLERY. 
[Case 14.] The Pigs, which occuj)y Case 14, have long narrow skulls, 
tuherculated molars, large curved canines, and four-toed feet, the 
bones ot all the toes being separate, and not united to form a 
cannon bone. The dental formula of the Common Pig is I. 
C. Pm. M. I X 2 = 44, giving the same number and distri- 
bution of teeth as in the majority of Mammals of the earlier 
Tertiary periods, but which is now found only in the genus Stis 
and two genera of Insectivora. 
Skeletons are exhibited of a ’Wild Boar {Siis scrofa), Wart-hog 
{Phacochosrus) , and Peccary [Dicotyles) ; and skulls, among others, 
of the Pygmy Hog [Sus salvanius), Babirusa (B. alfurus), and 
River-Hogs [Potamochcerus). There is also (Div. F) an interesting 
series of upper jaws of Wart-Hogs, showing the variation they 
present in the presence or absence of the small upper incisor teeth. 
The Ruminant Artiodactyles have molar teeth with crescentic 
ridges. Their division into the Tylopoda, Tragulina, and Pecora 
has been already noted, p. 40. 
The Tylopoda, or Camel tribe, differ from the other Ruminants 
in the presence of a pair of small incisor teeth in the upper jaw, in 
the absolute suppression of the outer toes, and in their having no 
horns in either sex. 
The Camels are represented in Case 15 by a skeleton of the 
Dromedary or one-humped species [Camelus dromedarius) and by 
skulls both of that species and of the true or two-humped Camel 
(C. bactrianiis) . Of the Llamas, there is a skeleton of the Llama 
(Lama ylama), which shows the close affinity of these animals to 
the Camels, the skeleton and skull being merely smaller forms of 
the same type. 
[Case 15.] The Trayulina (Div. E), containing the Common and Water 
Chevrotains, are distinguished by the long canine teeth of the 
males, by the shape of the odontoid process of the second 
vertebra, which is conical, by the presence of four complete digits 
to all the feet, all the bones of the leg being likewise fully de- 
veloped, and by the spongy structure of the auditory bullae. 
The Pecora are characterized osteologically by the development 
of horns in the majority of the sj)ecies, at least in the male sex, 
by the total absence of upper incisors, by their crescent-shaped 
odontoid processes, rudimentary or absent outer digits, incomplete 
fibulae, and simple inflated auditory bullae. 
