NERVOUS SYSTEM. VERTEBRATA. 



273 



This brain incidentally illustrates various points in the 

 arrangement of sulci. The greater stability of the post- 

 sylvian as compared with the postlateral is shown by the 

 complete absence of the latter. The proximity of the 

 suprasylvian to the " Sylvian " is suggestive of its absorp- 

 tion in the latter, as in the Seals and, in another sense, in 

 the Primates. 0. C. 1325 N c. 



Mivart, Journ. Linn. Soc., vol. xix. 1886, p. 18. 



D. 355. The brain of Helictis subaurantiaca, ( ? ). 



Although this brain presents the common Arctoid cha- 

 racters, it conforms more especially to the Musteline type 

 (fig. 147). 



Fig. 147. (Nat. size.) 



SULC. SUPRAS. 



SULC. CRU. SULC. LAT 



SULC. ORB. 



Fig. 148. (Nat. size.) 



SULC.PRECRU. 

 SULC. ORB. 



..SULC"SPLEN'.' 



It presents a most extraordinary feature for a Carnivore 

 in that the intercalary prolongation of the calcarine sulctis 

 (the so-called " splenial ") extends on to the dorsal surface 

 and is prolonged forward parallel to the interhemispheral 

 cleft and ultimately joins the transverse crucial (fig. 148). 



VOL. II. 



