774 MR. W. N. PARKER ON THE INDIAN TAPIR. [DcC. 19, 



hemispheres form marked oval elevations between the olfactory 

 lobes and optic chiasma. 



Dareste' gives a short description and diagram of the convolutions 

 of the brain in the American Tapir ; and Broca, in his admirable 

 memoir (Anatomie comparee des circonvolutions cerebrales'^), de- 

 scribes the convolutions more fully, giving diagrams of an external, 

 an internal, and a posterior view of the hemisphere ; he, however, 

 does not state to what species his description refers. Dareste's 

 figure differs entirely from the specimen under consideration, which 

 also does not altogether agree with Broca's account. 



The posterior part of each hemisphere presents three main gyri, 

 which are much twisted, and differ considerably on opposite sides ; 

 the outer of these is folded on itself at the posterior end, and is 

 broader than the other two taken together. These constitute the 

 four parietal convolutions of Broca. The internal and external gyri 

 can be traced to the frontal region of the hemisphere ; while the 

 middle one, which is the simplest, stops short at about the line of 

 junction between the anterior and middle thirds. The external 

 gyrus is much folded in front. 



At about the middle of the hemispheres, the inner border of the 

 internal gyrus passes gradually outwards, so that the posterior part 

 of the callosal gyrus can be seen from above, thus differing from tiie 

 Rhinoceros and resembling the Horse. There is a deep groove 

 between the parietal and temporal lobes ; and this fissure (Broca's 

 "arc inferieur de la scissure limbique") extends forwards along a 

 curved hue to the rudimentary Sylvian fissure, beneath which are 

 seen the small convolutions of the island of Reil ; these are consti- 

 tuted by the temporo-frontal fold, the other sub-Sylvian (temporo- 

 parietal) fold described by Broca not being present. The temporal 

 lobe is smooth. 



The corpus geniculatum and corpus mamillare are well marked. 

 The pons Varolii is rather narrow, while the crura cerebri are long. 



The cerebellum, though relatively larger, resembles closely that 

 of the Horse, and presents the same irregular appearance. 



On viewing the hemisphere from the inside (Plate LIX. fig. 4), 

 the calloso-marginal sulcus (" arc supcrieur de la scissure limbique" 

 of Broca) is seen to bend down in front of the corpus callosum, as in 

 the Rliinoceros and Horse, and does not, as in the Sheep and many 

 other Ungulates, become superficial anteriorly. The large callosal 

 gyrus is divided into two in its posterior part by a longitudinal 

 fissure. 



Teeth. — All the milk-teeth wt^re in place, the dental formula beino- 

 •^•i- sEijj ^- c- lEi) d.m. 1^. This corresponds with the usual state- 

 ments on the subject. Behind these, traces of the developing first 

 and second true molars could be detected in the dry skull, Iving 



' "Troisieine memoire sur les circonvolutions dii cerveau eliez lea Mamuji- 

 teres," Ann. d. Sci. Nat. 4« serie, Zool. iii. 1855, p. 65. 

 Eevue d'Anthropologie, t. vii. 1878, p. 385. 



