ANOPLOTHERES, RUMIN^AXTS, AND TAPIRS. 65 



even number, because it offers in this part of its organ- 

 ization some transitional features between the dental 

 characters of the typical members of the isoclactyle 

 and of those of the anisodactyle ungulata. 



"All the kinds of teeth are retained and in almost 

 normal numbers in both jaws, with as little unequal 

 or excessive development as in the anoplothere,* but 

 the prolongation of the slender jaws carries the canines 

 and incisors to some distance from the grinders, and cre- 

 ates a long diastema, as in the ruminants f and tapirs. J 



* "The anoplothere was one of tlie earliest forms of hoofed 

 quadrupeds introduced upon the surface of this earth, and it is 

 characterized by the most complete system of dentition. It not 

 only possessed incisors and canines in both jaws, but they were 

 so equally developed that they formed one unbroken series with 

 the premolars and molars, which character is now found only 

 in the human species. The dental formula is r I., 3—3, 3—3 ; 

 C, 1-1, 1-1 ; P. M.,4-4. 4-4; M., 3-3, 3-3=44. The An- 

 oplothere Commiine was the size of an ass, and, with the other 

 species of the extinct genus, had a cloven hoof, like the Rumi- 

 nants, but the division extended throufjrh the metacarpus and 

 metatarsus. The anoplothere was an animal of aquatic habits, 

 and had a very long- and strong tail, which Cuvier conjectures 

 to have been used like that of the otter in swimming." — Oice?i. 



f " The ordinary dental formula of the Ruminantia is : I. 

 (upper jaw), 0-0, (lower jaw), 3—3 ; C, 0—0, 1—1 ; P. M., 3-3, 

 3—3 ; M., 3—3, 3—3=32. The antelopes, the sheep, and the 

 ox, which are collectively designated the 'hollow-homed ' rumi- 

 nants, present this formula. It likewise characterizes many of 

 the ' solid-horned ' ruminants, or the deer tribe, the exceptions 

 having canine teeth in the upper jaw in the male sex, and some- 

 times also in the female, thoug'h they are always smaller in the 

 latter.** — Owen. 



X " The dental formula of the tapir is : I., 3—3. 3—3 ; C, 1 — 1, 

 1-1 ; P. M., 4-3, 4-3 ; M., 3-3, d~d^ 42.''— Owen. 



It is noteworthy that the dentition of the tapir corresponds 

 precisely in number with that of the horse, provided the latter's 



