CARXIVORA THE SKULL. 109 



initiating bluntly, does not articulate with the metacarpus, the pollex or thumb 

 being absent. 



The metacarpal bones are 4 in number. The middle pair are large, the side 

 pair small ; the large ones articulate with each other, and with their relative 

 small ones superiorly. Each terminates distally, as the single one of the 

 horse, but the middle pair are the sole weight-carriers, for the lateral ones do 

 not rest upon the ground. In each of the four digits there are three phalanges, 

 with their accessory sesamoid and navicular bones. 



PELVIS AND PELVIC LIMB. 



The os innominatum presents the same general characters as that of the 

 ruminant ; it is, however, distinguished by the form of the ilium, which is very 

 convex on its anterior border and crest, and by the absence of the protuberance 

 on the inferior symphysis. The femur differs little from that of the ox, except 

 in its more contracted neck, which is about on a level with the trochanter 

 major ; the trochanter minor is wanting. The tibia resembles that of the 

 ruminant ; its anterior tuberosity is notched, and the external malleolus is 

 supplied by the distal end of-the fibula. The fibula extends the whole length 

 of the tibia, articulating with it at both extremities, and distally with the 

 astragalus and calcaneum. The tarsus presents no important deviation from 

 the typical joint, except that the cuneiforme medium is divided, hence there 

 are in the lower row the ecto, meso, and endo-cuneiform bones ; the distal 

 articular surface of the astragalus articulates partly with the cuboid bone. 

 The metatarsus and phalanges closely resemble those of the anterior limb. 

 There is a very rudimentary fifth metatarsal bone on the inside, a vestige 

 probably of the hallux or great toe. 



CAEXIVORA. 



In this order our descriptions allude mostly to the Dog, that animal being 

 an excellent type of the order, and one easily obtained. 



AXIAL SKELETON. 



THE SKULL. 



The occipital bone of the Dog is very strong, and triangular behind, termina- 

 ting in a sharp pointed crest. The tuberosity is not well "marked ; the styloid 

 processes are short, and the condyles large. The foramen lacerum basis cranii 

 is divided into two portions by the auditory bulla, which is large and rounded ; 

 the basilar process is long and thick. The Wormian bone is united to the 

 occipital ; the ossific tentorium is large. The parietal bones are very convex, 

 in some breeds meeting in a sharp ridge, continuous with the occipital crest. 

 The frontal bones are triangular, and present along their middle a hollow, 

 more or less marked. The orbital process is simply a peak, the arch being 

 completed by a ligament ; there is no supraorbital foramen ; the frontal bone 

 articulates with the superior maxilla. The temporals are not divisible into 

 distinct pieces, as in the horse ; the zygomatic processes are large, and project 

 very much, forming capacious temporal fossae, and having glenoid cavities, 

 which are elongated transversely, for the condyles of the inferior maxilla. 



