THE BEaIN IX THE EDENTATA. 351 



that in this large brain the pallial snlci wonld bo snfficiently ^voll developed to settle 

 these difficult morphological problems *. 



The most noteworthy feature of the brain of the gigantic extinct Arniadillo is the 

 relatively diminutive proportions of the cerebral hemispheres. In Ghjptodon we find 

 hemisjDheres only slightly larger than those of Priodoii ; and the relatively small pallium 

 apjiears to be almost, if not quite, smooth. The extreme macrosmatism of the living 

 Armadillo is even more exaggei-ated in the extinct forms, and especially Gbjpfodou, 

 Avliich exhibits enormous conical olfactory bulbs attached to the hemisjiheres by means 

 of large peduncles. 



Thanks to Max Weber, we ha^e now a more exact knowledge of the l)rain of the 

 Pangolin than the works of Pouchet and Gervais provide. Por in bis important monograph 

 upon Manis Weber gives us some excellent figures of the brain, accompanied by a brief 

 concise description. I have examined two brains illustrative of this genus. 



As I have already pointed out, the anterior rhinal is quite distinct from the posterior 

 jhinal fissure. The latter becomes continuous, as we found to be the case in Dasypus, 

 with a pallial sulcus which extends obliquely upward and forward to\vard the anterior 

 pole of the hemisphere. Weber calls this the "/issnra imrsylvla,'' but says that its 

 homology must remain doubtful. I think that we may, without hesitation, regard it 

 as the homologue of the sulcus /3, Mhicli corresponds to the presylvkm (Owen) or supra- 

 orbital (Flower) sulcus of other mammals. In Weber's specimen this sulcus becomes 

 directly continuous with a well-defined and typical sagittal sulcus (y), in a similar mannei" 

 to the arrangement we have already noted in Orycteropxs and in some of our specimens 

 of Cliolpa-MS {vide Weber's figures G7 and 68). In the better-preserved of my two 

 specimens the supraorbital sulcus (/3) is not connected to the sagittal sulcus (7). 



We may, in agreement with Max Weber, regard the area just below the junction of 

 the posterior rhinal fissure with the supraorbital sulcus (/3) as the fossa Sylvii ; but I must 

 entirely disagree with him when he describes a Sylvian fissure in addition to tl)is. 



Thus he says :— " Aus der Possa Sylvii ziehen zwei weitere Purchen : die eine [/3] 

 nach vorn und oben, um in die spater zu nennende Pissura sagittalis einzutreten, die 

 andere vertikal noch oben, umweiterhin nach hinten umzubeugen. Letztere mochte ich 

 als Pissura Sylvii deuten, wahrend die Homologie der ersteren mir zw^eifelhaft gehliel)en 

 ist." t This region of the brain is unfortunately not shown clearly in Weber's figures, 

 because it is not easy to determine which are true sulci and which merely vascular 

 depressions. In the only brain of Hauls upon which I have been able to examine this 

 region there is a large arcuate fissure, which appears to spring from the lowermost part 

 of the supraorbital sulcus, and behaves in a manner exactly similar to the suprasylvian 

 sulcus (^) in the Sloths. The homology of this sulcus with the suprasylvian sulcus of 



* In a popular work edited by Martin Diineau (Casscll's ' Xatural Histor)- : ' London) a figure, entitled 

 " Krain of the Armadillo," accompanies a description oi Priodon (vol. iii. p. IS:}). The brain is as richly convoluted 

 as that of the Sloths, but is utterly unlike that of any Armadillo I know, and is certainly not the brain of Priudon ; 

 for, apart from the configuration of the cerebrum and cerebellum, the olfactory bulb is relatively as small as that of 

 Cydotarus, while all the Armadillos have enormous bulbs. 



t Max Weber, J Zool. Ergebnisse, p. 87. 



48* 



