312 PEOF. G. ELLIOT SMITH OX THE 



sulcus. In an Ape's hrain this would be called " infei-ior temporal." In this brain the 

 sulci X and ij appear to be joined to the coronal to form a triradiate pattern. 



Tliere is also a small collateral sulcus (fig. 12, b), such as the brain of Lemur presents. 



Beddard says that " there appear to be more differences between the brain of 

 [Ni/eficebits tardigradns] and that of its congener Nyctlcehus javanicus than loetween 

 the different species of Lemur .... the brain is more rounded in front, and the 

 cerebellum more fully exposed than is indicated in Sir W. Flower's figure of iS'.jaoanicus. 

 The angular fissure [Beddard thus refers to tlie sulcus designated / in my account and 

 mistakes it for the ' lateral '] is short and instead of l)eing straight it is crescentic . . 

 the concavities facing each other. . . Tlie infero-froutal [coronal] seems to be less 

 conspicuous tlian in the other species of the genus and on one side of the brain it 

 ran back to join the curved (anteriorly convex) presylvian fissure [tlie sulcus .r], the 

 homologue (?) of which latter in N. javanicus lias a totally different direction. The 

 ])arieto-occipital ('Simian') fissures [postlateral sulci] are better developed than in 

 N. javanicus and reach the intercerebral sulcus" (Proc. Zool. Soc. 1895, p. 111). 



The differences in shape which Beddard regards as specific features I have been 

 unable to find upon exaniining a series of crania, and the features of the sulci upon 

 which he lays stress are individual variations such as also occur in undoubted examples 

 of the species tarcUgradus. So far as one can be guided by the evidence of cerebral 

 anatomy, there is no reason for splitting up the species tardigradus to make another 

 species {javanicus). 



There can be little doubt that the brain which Chudziuski described under the title 

 " Loris (jrocilis " (Bull. Soc. d'Anth. 1895, p. 43G) is really that of Nyciicehus tardi- 

 f/radus. It ])resents the arrangement of sulci typical of the latter ; and this is very- 

 different from that of Loris. The Sylvian fissure is joined to the lateral in the typical 

 manner, and the latter ends in a bifid extremity, which Chudziuski calls " portion externe 

 de la scissure occipitale " ; this is the postlateral sulcus. 



The sulcus/, the postsylvian and the triradiate complex of the sulci .r, y, and coronal 

 resemble those described above in the specimen belonging to the College of Surgeons. 

 There is a small sulcus behind the upper end of the postsylvian. 



Ziehen based his account of the bj-ain in this genus (Arch. f. Psych, xxviii. 

 pp. 902-906) on four specimens (one of Avhich is in the College of Surgeons, and another 

 in the British Museum). He calls the mesially-bent extremity of the lateral sulcus the 

 " Eiidiment der Fissura parieto-occipilalis lateralis."' [In respect to this sulcus the 

 condition represented in his drawing lesembles my type si)ecimen.] 



The sulci which I have labelled/', x, and y he regards as representatives of the sulcus 

 centralis. 



The sulcus behind the iipper end of the postsyl\i;ui (his "temporalis superior") 

 is called " temporalis inferior." Another small sulcus behind the loAver part of the 

 postsylvian, which I have not seen in any of my specimens, is regarded as the lower 

 part of the same sulcus. 



He represents a small separate furrow above the postsylvian, such as is olten i)r( sent 

 in the Lemurs {d) ; and the connecting limb of the supra- and postsylvian sulci is also 



