34S 



PROF. G. ELLIOT SMITH ON THE 



transverse furi'ows (in Bedclard's specimen there is only one, whieli is labelled " parieto- 

 occipital ") representing the postlateral (transverse occipital) sulcus. The anterior end 

 of the sulcus extends downward in front of the Sylvian fissure for a short distance, so as 

 almost to reach the caudal end of a sagittal sulcus (coronalis). The latter is bent in an 

 ol)tuse angle in the brain I have examined ; in Beddard's specimen it is apparently 

 represented by two separate sulci (labelled "infero-frontal ") in the same straight line ; 

 and in the skull of Kirk's Galago there is a ridge representing an extensive straight 

 sulcus directed obliquely forward and mesially, as in Lemur. Above the sulcus coronalis 

 tliere is a faint depression (/), such as is found in Lemur. 



On the mesial surface the sulci are grouped as in Garnett's Galago. There is, 

 however, a sulcus a. 



from an examination of the skull of GaJago 31onieiri (lloyal College of Surgeons, 

 specimen No. 285, Osteological Series), I can definitely state that the brain is of 

 the same shape as that of Garnett's Galago, and presents rhinal and Sylvian fissures and 

 an orbital sulcus of the same type. There must have been, however, an extensive, 

 tliough shallow, postsylvian sulcus, the upper end of which curves upward and forward 

 toward a lateral sulcus which was prolonged unusually far back. There was also 

 an extensive coronal sulcus, like that of Lemur. 



In a skull of Galago Alleni the most noteworthy feature is the impression of a 

 crescentic or boomerang-shaped coronal sulcus. 



Yig. 18. 



Fig. IS. 



Fig. 20 



Kg. 21. 



spc. 



.TC . 



Fig. IS. — Microcehiis SmitJu. Dorsal aspect of the bi-ain. Nnt. size. 

 Fig. 19. — Microcehvs SmitJii. Left lateral aspect of the brain. x 2. 



YVr^. 20. — Microcchis ,Smithi. Lateral aspect of the loft cerebral hemisphere, dissectcfl to show the hippo- 

 campus and the calcarine eminence, x 2. 

 Fig. 21. — .Vicrocehiis Smith). Mesial aspect of the right cerebral hemisphere. x 2. 



The cerebral hemisphere of the small brain of Jlicroeebus Smithi reseml)les that 

 of Galago in shape. It is 15-5 mm. long (without the olfactory bulb, which projects 

 almost 3 mm. in front of the hemisphere) ; its maximum depth is 10 mm., and its 

 greatest breadth 7-5 mm. (each hemisphere). The lateral caudo-ventral margin is 



