40 



Camel. And the value of this distinction has been exag- 

 gerated owing to the common conception of the ribs as special 

 bones distinct from the vertebras, and their non-recognition as 

 parts of a vertebra equivalent to the neurapophyses and other 

 autogenous elements. 



The vertebral formulae of the Artiodactyle skeletons shew 

 that the difference in the number of the so-called dorsal and 

 lumbar vertebras does not affect the number of the entire 

 dorso-lumbar series : thus the Indian Wild Boar has d. 13, 

 1. 6 = 19 ; the Domestic Hog and the Peccari have d. 14, I. 

 5 = 19; the Hippopotamus has d. 15, I. 4 = 19 ; the Gnu and 

 Aurochs have d. 14, I. 5 = 19 ; the Ox and most of the true 

 Ruminants have d. 13, I. 6 = 19; the aberrant Ruminants have 

 d. 12, I. 7 = 19. The natural character and true affinities of 

 the Artiodactyle group are further illustrated by the absence 

 of the third trochanter in the femur, and by the place of per- 

 foration of the medullary artery at the fore and upper part of 

 the shaft, as in the Hippopotamus, the Hog, and most of the 

 Ruminants. The fore part of the astragalus is divided into 

 two equal or subequal facets : the os magnum does not exceed, 

 or is less than, the unciforme in size, in the carpus ; and the 

 ectocuneiform is less, or not larger, than the cuboid, in the 

 tarsus. The digit answering to the third in the pentadactyle 

 foot is unsymmetrical, and forms, with that answering to the 

 fourth, a symmetrical pair. If the species be horned, the 

 horns form one pair, as in most Ruminants, or two pairs, as 

 in the four-horned Antelope and Sivathere ; they are never 

 developed singly, of symmetrical form, from the median line. 

 The post-tympanic does not project downward distinctly from 

 the mastoid, nor supersede it in any Artiodactyle ; and the 

 paroccipital always exceeds both those processes in length. 

 The bony palate extends .further back than in the Perisso- 

 dactyles ; the hinder aperture of the nasal passages is more 

 vertical and commences posterior to the last molar tooth. The 

 base of the pterygoid process is not perforated by the ecto- 

 carotid artery. The crowns of the premolars are smaller and 



