1889.] ANATOMY OF RHINOCEROS SUM ATRENSIS. 9 



Khiiioceros were kept for some weeks while the muscles were in 

 course of dissi^ction. 



Ill performinjj; this task we were greatly assisted by Mr. Tonks, 

 now Physician at the Free Hospital, Grays Inn Road ; for most of 

 the drawings which illustrate this paper (woodcuts, figs. 3-10) we are 

 also indebted to that gentleman. 



Both the individuals were referred on tht-ir arrival at the Gardens 

 to Rhinoceros sumatrensis ; subsequently Mr. Sclater considered 

 that they were probably examples of his species Rhinoceros lasi- 

 otis, of wliich the type is still living in the Gardens. Without 

 goins fully into the question of the distinctness of Rh. lasiotis from 

 Rh. sumatrensis, which cannot be done properly until the death of 

 the type specimen, it may be remarked that there are no characters 

 in the skull which would seem to justify such a distinction. In 

 making a com})arison of the skull of these specimens with Rh. 

 sumatrensis, particular attention was paid to a paper by Frof. Flower 

 in the ' Proceedings ' ' of this Society, in which a skull possibly 

 identical with Mr. Sclater's lih. lasiotis was comnared with Bh. 

 sumatrensis. AssrUUiing that problematical skull to represent Rh. 

 lasiotis, it is clear that neither of the individuals discussed in the 

 present paper belong to that specie?, for in all the points raised by 

 Prof. Flower these individuals are typical Rh. sumatrensis. 



With regard to the visceral anatomy of this species we have not 

 much to add to the description by Garrod ; and tlie species dues not 

 differ materially from Rh. sondaicus, which we have described some- 

 what fully in the ' Transactions' (vol. xii.) of this Society. 



Garrod describes the ridges upon the hard palate of Rh. sumatrensis 

 but gives no figure of it. The accompanying drawing (fig. 1, p. 8) 

 has been made for the purpose of a comparison with the hard palate 

 of Rh. sondaicus, which has been figured by us in our memoir upon 

 that Rhinoceros. 



The caecum and the neighbouring parts of the intestines have been 

 figured by Garrod ; and as his figure illustrates the principal points 

 in the anatomy of this region of the gut, we have thought it hardly 

 worth while to give a further illustration. 



In the loop which is formed by the commencement of the colon, 

 the distal portion is of a narrower calibre, as shown in Garrod's 

 figure. 



The mesentery whicli unites the opposite sides of the loop has a 

 pecuhar fold upon it which is illustrated in our figure of Rh. 

 sondaicus. In that Rhinoceros the fold in question {loc. cit. pi. xxxiv. 

 figs. 1-3) arises near to the caecum and receives a branch from one 

 of the divisions of the colic artery ; at the opposite extremity of the 

 colic loop the band divided into two, whicli were attached to the 

 surface of the mesentery uniting the parietal sections of the colon ; 

 at this point the artery borne by the fold also divides and becomes 

 continuous at two points with the colic artery. It appeared to us 

 at the time we were investigating the anatomy of Rh. sondaicus 

 that the azygos artery borne by this fold might serve to supply this 



1 P. Z. S. 1878, p. 634. 



