A 
based on the principle of Cephalization—Herbivores. 169 
(2.) Tapiroids—Without a nasal horn. Snout elongate, often im- 
perfectly prehensile. 
a, Tapirids. 
b. Paleotherids. 
(3.) Hyracids.— Without a nasal horn. Snout not elongated. 
8. SuIDEANS.—Snout elongate, but not at all prehensile. 
Paridigitate. 
(1.) Suids. 
(2.) Hippopotamids. 
II. Sthenomeres. 
Metasthenic. Long-amplificate, even when gross-amplificate. 
out no ower-organ. Horns, when any, proceeding from 
the endoskeleton, frontal. 
1. Sourpeps.— Without horns. Imparidigitate. 
(1.) Equids, 
(2.) Macrauchenids. (?) 
2. Ruminants.—Having horns in the typical group, except 
often in females. Paridigitate. 
- (1.) Cornigers—Having horns. Frontiferient. 
a. Cervids. 
b. Antilopids. 
ce. Camelopardalids. 
({2.) Nudifronts—Without horns. Not frontiferient, feeble in self- 
defense. ‘ 
a, Camelids. 
» 6. Moschids. 
ec. Anoplotherids. 
? 
‘TIL. Sirenians. 
Urosthenic, natatorial. Having a large caudal fin for swim- 
ming. Posterior limbs wanting. 
Manatus, Halicore or Dugong, Rytina, etc. 
In the following enumeration of the distinctions of the several 
subdivisions, I confine myself almost entirely to those character- 
istics which are obviously based on the principle of cephaliza- 
tion, omitting the many anatomical details to be found in zoolo- 
gical treatises, 
A. Subdivisions of the Sthenorhines. 
(1.) The Proboscideans are distinguished by the high charac- 
teristic of having in the proboscis a prehensile organ of great 
