Chap. IV. DIFFERENCES IN THEIR SKELETONS. 



123 



Fig 8. — Part of Zygomatic Arch, showing the 

 projecting end of the malar bone of the 

 auditory meatus: of natural size. Upper 

 figure, Wild Rabbit. Lower figure, Lop- 

 eared, hare-coloured Rabbit. 



form"2° of the occiput, instead of being truncated, or proje3ting slightly 

 as in the wild rabbit, is in most 

 lop-eared rabbits pointed, as in 

 fig. 9, C. The paramastoids rela- 

 tively to the size of the skull are 

 generally much thicker than in 

 the wild rabbit. 



The occipital foramen (Lg. 10) 

 presents some remarkable differ- 

 ences: in the wild rabbit, the 

 lower edge between the condyles 

 is considerably and almost angu- 

 larly hollowed out, and the upper 

 edge is deeply and squarely 

 notched ; hence the longitudinal 

 axis exceeds the transverse axis. 

 In the skulls of the lop-eared 

 rabbits the transverse axis ex- 

 ceeds the longitudinal; for in 

 none of these skulls was the 

 lower edge between the condyles 

 so deeply hollowed out ; in five 

 of them there was no upper 

 square notch, in three there was a trace of the notch, and in two 

 alone it was well developed. a r n 



These differences in the 

 shape of the foramen are 

 remarkable, considering 

 that it gives passage to so 

 important a structure as 

 the spinal marrow, though 

 apparently the outline of 

 the latter is not afi"ected 

 by the shape of the passage. 



In all the skulls of the 

 large lop-eared rabbits, the 

 bony auditory meatus is conspicuously larger than in the wild 

 rabliit. In a skull 4'3 inches a r 



in length, and which barely 

 exceeded in breadth the 

 skull of a wild rabbi 

 (which was 3'15 inches in 

 length), the longer diameter 

 of the meatus was exactly 

 twice as great. The orifice 

 is more compressed, and 

 its margin on the side nearest the skull stands up higher than 



Fig. 9. — Posterior end of skull, of natural size, showing 

 the inter-parietal bone. A. Wild Rabbit. B. Feral 

 Rabbit from island of P. Santo, near Madeira. 

 C. Large Lop-eared Rabbit. 



Fig. 10.— Occipital Foramen, of natural stze, in — 

 A. Wild Rabbit; B. Large Lop-eared Rabbit. 



Waterhouse, ' Nat. Hist. Mammalia,' vol. ii. p. 36 



