Chap. IV. 



DIFFERENCES IN THEIR SKELETONS. 



121 



Fig. 12. — Atlas Vertebras, of natural size ; 

 inferior surface viewed obliquely. 

 Upper figure, Wild Rabbit. Lower 

 figure, Hare-coloured, large, Lop-eared 

 Rabbit. a, supra-median, atlantoid 

 process ; b, infra-median process. 



seven as the number for the whole genus Lepus. The caudal vertebras 

 apparently differ by two or three, but I did not attend to them, and they 

 are difficult to count with certainty. 



In the first cervical vertebra, or atlas, the anterior margin of the 

 neural arch varies a little in wild specimens, 

 being either nearly smooth, or furnished 

 with a small supra-median atlantoid pro- 

 cess ; I have figured a specimen with the 

 largest process (a) which I have seen ; but 

 it will be observed how inferior this is in 

 size and different in shape to that in a 

 large lop-eared rabbit. In the latter, the 

 infra-median process (6) is also proportion- 

 ally much thicker and longer. The alae are 

 a little squarer in outline. 



Third cervical vertebra. — In the wild rabbit 

 (fig. 13, a a) this vertebra, viewed on the 

 inferior surface, has a transverse process, 

 which is directed obliquely backwards, and 

 consists of a single pointed bar ; in the fourth 

 vertebra this process is slightly forked in 

 the middle. In the large lop-eared rabbits 

 this process (b a) is forked in the third ver- 

 tebra, as in the fourth of the wild rabbit. 

 But the third cervical vertebrae of the wild and lop-eared (a b, b b) rabbits 

 differ more conspicuously when their anterior articular surfaces are com- 

 pared ; for the extremities of the 

 antero-dorsal processes in the 

 wild rabbit are simply rounded, 

 whilst in the lop-eared they are 

 trifid, with a deep central pit. 

 The canal for the spinal marrow 

 in the lop-eared (b b) is more 

 elongated in a transverse direc- 

 tion than in the wild rabbit; 

 and the passages for the arteries 

 are of a slightly different shape. 

 These several differences in this 

 vertebra seem to me well de- 

 serving attention. 



First dorsal vertebra. — Its 

 neural spine varies in length in 

 the wild rabbit ; being sometimes 



very short, but generally more than half as long as that of the second 

 dorsal; but I have seen it in two large lop-eared rabbits three-fourths 

 of the length of that of the second dorsal vertebra. 



Ninth and tenth dorsal vertebra?. —In the wild rabbit the neural spine of 

 the ninth vertebra is just perceptibly thicker than that of the eighth ; and 



Fig. 13.— Third Cervical Vertebra, of natural size, 

 of— A. Wild Rabbit; B. Hare-coloured, large, 

 Lop-eared Rabbit. a, a, inferior surface; 

 b, b, anterior articular surfaces. 



