RHINOCERO TID^E 



407 



and reference has already been made to the resemblance between 

 the visceral anatomy of these species. 1 The form of the stomach 

 is very similar to that of the Horse. The liver (Fig. 171) has a 

 comparatively large caudate lobe, but is chiefly remarkable for the 

 peculiar shape of the Spigelian lobe, which mainly consists of a thin 

 strip of tissue, 8 inches long, f inch wide, and \ inch deep. The 

 small intestine, in place of the villi of R. unicornis, has throughout 

 the greater part of its length a uniform series of thin and nearly or 

 quite continuous transverse foldings, like the valvulae conniventes 

 of the human small intestine. There is no gland behind the foot. 





FIG. 171. Posterior aspect of the liver of Rhinoceros sumatrensis. re, Right central lobe ; 

 rl, right lateral lobe ; Ic, left central lobe ; II, left lateral lobe ; e, caudate lobe ; sp, Spigelian 

 lobe. (From Garrod, Proc. Zool. Soc. 1873, p. 102.) 



The post-glenoid and post-tympanic processes of the squamosal do 

 not unite below the auditory meatus. The presence of a lateral 

 nasal diverticulum, like that of the Horses and Tapirs, has been 

 Verified only in this species, although it doubtless occurs in the 

 others. 



Atelodine Group. In the adults the incisors and canines quite 

 rudimentary or entirely wanting. Nasal bones thick, rounded and 

 truncated in front. Well-developed anterior and posterior horns in 

 close contact. Skin without any definite permanent folds. 



The two well-marked existing species are peculiar to the African 

 continent. 



1 For the internal anatomy of R. sumatrensis see Garrod, Proc. Zool. Soc. 

 1873, p. 92 ; and Beddard and Treves, loc. cit. 



