ANATOMY OF THE SONDAIG EHINOCEEOS. 197 



therefore to compare them carefully with Owen's description and with the conditions 

 observed by us in Bh. sonclaicus ; on a priori grounds it would seem more likely that 

 the Sumatran Ehinoceroses would differ from both Bh. indicus and Bh. sonclaicus than 

 that the two latter should differ in so remarkable a manner from each other. 



The 2>eim appears to correspond closely to that of Rhinoceros indicus ; it is hardly 

 worth while to describe it in detail, as Prof Owen's description would apply almost 

 word for word to the present species ; it is important, however, to record the fact that 

 there is this similarity, since Mr. Forbes has pointed out that the glans penis of 

 Bh. sumatrensis is somewhat different in shape from that of Bh. indicus. 



The penis is provided with two retractores penis and two levatores penis ; the latter 

 unite together and are attached to the penis about 10 inches from the end of the bulb 

 by a thick tendon about the size of the thumb. From this point the tendon passes 

 along the dorsal surface of the organ as far as the glans. 



The retractores penis are inserted for a space of about 4 inches on to the ventral 

 surface of the penis. 



Brain. 



The brain of Bhinoceros sondaicus is illustrated on PI. XXXVII. by two figures ; one 

 (fig. 2) represents the superior surface of the organ, the other (fig. 1) the inferior 

 surface. It has been already mentioned that the arterial system of the animal was 

 successfully injected : we found on examining the brain that the arteries at its base 

 were likewise filled with a mass of injection and rendered therefore very conspicuous ; 

 the figure shows the distribution of the artei-ies. Both drawings were made after the 

 brain had been hardened in spirit. 



The convolutions of the cerebral hemispheres appear to be not very different from 

 those of Bh. indicus, and both rather less complicated than what is met with in 

 Ceratorhinus sumatrensis, judging from the figures of these two brains which illustrate 

 the papers of Sir Richard Owen and Prof. Garrod ; in details, however, the convolutions 

 of the brain of Bh. sondaicus are not precisely like Bh. indicus ; our figure may be 

 compared with Owen's. 



EXPLANATION OF THE PLATES. 



PLATE XXXIII. 



Stomach and spleen, including gastrosplenic omentum ; the blood-vessels injected. 

 ce, oesophagus ; d, duodenum ; s]^, spleen ; s.c, superior cul-de-sac ; i.c, inferior 

 cul-de-sac; ^j.c, pyloric cul-de-sac; G.a, gastric artery (s, its superior branch; 

 1, its inferior branch) ; s.p.d, superior pancreatico-duodenal arteiy ; G.e.d, 

 gastro-epiploica dextra artery. 



