488 ANATOMY OF VERTEBRATES. 



more extensive and favourable attacliment of accessory fascicles. 

 Each toe has its distinct metacarpal or metatarsal. The digits, 

 especially in the fore-limb, enjoy freedom of motion and power of 

 reciprocal approximation and divarication ; the terminal phalanx is 

 compressed and deep, with a plate of bone reflected forward from 

 the basal periphery, beyond which the apex of the phalanx pro- 

 jects like a peg from a sheath : the claw is fixed upon the peg, its 

 base being firmly wedged into the interspace betAveen the peg and 

 the sheath. In the Felines, which are the most perfect carni- 

 vorous Unguiculates, the claw phalanx is retractile. The fore- 

 paw, so armed, is attached to the radius and ulna, which are entire, 

 distinct, and strong bones : these articulate with the humerus by 

 a joint, which, although well knit, allows both freedom of motion 

 in bending and extending, and also a reciprocal play of the two 

 bones, the radius rotating on the ulna, and carrying Avith it, by 

 the greater expanse of its lower end, the paw, which can thus be 

 turned ' prone ' or * supine,' whereby its efficacy as an instrument 

 for seizing and tearing is enhanced. The humerus has strong 

 ridges from the outer and inner sides above the condyles for ex- 

 tending the origins of the muscles of the paw ; and, to defend the 

 main nerve and artery of the fore-leg from compression during 

 the action of these muscles, a bridge of bone spans across them in 

 the feline, and some other Carnivora. The upper end of the 

 humerus has a long and strong deltoid ridge ; but the tuberosities 

 do not project beyond the round head of the bone so as to impede 

 its movements in the socket. The scapula is of great breadth, 

 with well-developed spine, acromion, and coracoid. A small 

 clavicular bone is interposed in most Carnivora between a muscle 

 of the head and one of the arm, giving additional force and de- 

 termination of action to them. Such are the chief modifications 

 of the framework of the unguiculate as contrasted with the 

 ungulate Gyrencephala. 



A. Vertebral Columri. — This part of the skeleton of Carni- 

 vora is modified in relation to the medium of life, degree of car- 

 nivority, and modes of motion of the species. In no Carnivore 

 do cervical vertebra3 articulate by ball-and-socket joints ; and in 

 all, the seventh has the transverse processes imperforate, consist- 

 ing only of diapophyses. The Harp Seal {Phoca groenlandica, 

 fig. 332) has 15 dorsal, d, 5 lumbar, L, 4 sacral, s, and 8 

 caudal. Ten pairs of ribs directly join the sternum, which 

 consists of eight bones : the manubrium, 52^, is much produced, 

 for extending the fore-and-aft origins of the pectoral muscles. The 

 neural arches of the middle dorsal vertebras are slender, leaviiio- 



