NERVOUS SYSTEM. VERTEBRATA. 375 



with that of Daubentonia, which presents a blunt occipital 

 pole, like that of a Dog's brain, the contrast exhibited 

 by Galago, in which the occipital pole approaches the 

 condition found in the Marmosets, is very striking. 



There are typically complete rhinal and Sylvian fissures, 

 a short rectilinear intraparietal sulcus, and a short orbital 

 sulcus alongside the anterior rhinal fissure (fig. 214). In 

 the place of the sulcus rectus and the parallel sulcus very 

 faint depressions are found. 



Fig. 215. .(Nat. size.) 



SULC. INTERCAL. 



SULC. ROS. 



On the mesial surface the typical Lemurine calcarine 

 and intercalary (calloso -marginal) sulci are found (fig. 215) . 



There is a considerable depressed area in the lower part 

 of the Sylvian fissure. It is chiefly covered by a temporal 

 operculum. 0. C. 1337 B b. 



Th. Ziehen, Arch. f. Psych., Bd. xxviii. 1896, p. 910. 



D. 543. The brain of a Smith's Dwarf-Lemur (Microcebus 

 smithii), ( ? ) . 



In this diminutive brain the sulci are few in number. 

 On the external surface, in addition to the Sylvian fissure, 

 there is a small sulcus rectus on the right side and a shallow 

 depression which may be the posterior rhinal fissure (in- 

 cisura temporalis of Human Anatomy) . 



There is a typical calcarine sulcus with the usual 

 Lemurine dorsal bifurcation. There is neither an inter- 

 calary nor a genual sulcus. 



It is interesting to compare this brain with that of the 

 peculiar little aberrant Prosimian Tarsius*, which possesses 



* There is no brain of Tarsnts in this Collection. For the opportunity of 

 examining several excellently-preserved specimens I am indebted to 

 Dr. Charles Hose of Borneo. 



