MORPIIOLOGT OF THE BEAIX IX THE MAiMMALIA. 



353 



of Iiidris brcvicaudatns in the Museum of the Pioyal College of Surgeons (Osteological 

 Series, No. 253) is represented in fig. 30. The actual brain of a representative of this 

 species has been well represented by Milne-Edwards (Hist. Madag. (2) tome vi. pi. 87. 

 figs. 4, 4 ft, 4 h, and 4(?). 



The draAvings published by Chudzinski (Bull. Soc. Anthrop. vi., vii), and reproduced 

 by Flatau and Jacobsohn (Handbuch, p. 203), appear to be borrowed from the figures 4 

 and 4 h of MiJne-Edwards's work. 



In my specimen (fig. 30) the upper end of the suprasylvian sulcus is strongly 

 recurv^ed, as it is in Propitlwcns. There is an unusually long postlateral sulcus, as 

 there is also iu Milne-Edwards's specimen. In the skull the ridge for the lateral sulcus 

 was shallow and ill-defined, and seemed to be broken into three parts (/', /", and l'"), of 

 which only the anterior (/'") was promineat. It seemed to be joined to the coronal 



Fig. 30. 



Fig. 30. — latins hrfvramdvliis. Left lateral aspect of a cranial cast. Xat. .si/e. 

 Fig. 31. — li',(/u's lamfja-. Lateral aspect of the left cerebral hemisphere. Xat. size. 



sulcus, which was much longer than in Milue-Edwards's specimen. Judging from the 

 condition represented by Milne-Edwards in the actual brain, I am inclined to regard 

 all three furrows, V, T, and V'\ in my specimen as representing the lateral sulcus. But 

 the relationship of the sulcus Z"' to the coronal seems to indicate that th(> lornici- sulcus 

 may also represent the furrow e of Propithecus (compare figs. 20, 27, 2.S, aud 2!J), which 

 may have fused with the lateral sulcus. This is a matter which can only be settled by 

 a careful study of a series of actual brains. This suggestion is put forwtird merely as 

 the solution which seems most likely to be correct. 



Chudzinski regards the sulcus which is formed by the union of the furrows /" and /" 

 in Milne-Edwards's specimen as the " central sulcus." But there is iu both specimens a 

 small sagittal sulcus /, which represents the similarly-labelled furrow in I'mpWiecm 

 and Lemur. 



The orbital sulcus is large aud asvmmctrieal in the two hemispheres. 



52* 



