396 PHYSIOLOGICAL SERIES. 



The Sylvian fissure and the intraparietal sulcus are con- 

 cur reiH. There is a simple parallel sulcus, which does not 

 approach the Sylvian fissure. Between the short central 

 suli-us and the intraparietal element of the complex there is 

 a short compensatory intraparietal sulcus. There is no 

 Simian sulcus, but there are two small sulci representing 

 the inferior occipital sulcus. There is a very deep sulcus 

 rectus and an H-shaped orbital sulcus. There is a deep, 

 -f might, unbranched calcarine sulcus. The essentially 

 calcarine-compensatory nature of the parieto-occipital sulcus 

 is shown by the fact that as the result of the peculiarity of 

 the calcarine sulcus, the parieto-occipital is represented 

 chiefly by a sulcus parallel to the almost horizontal calcarine, 

 which is merely analogous to, and cannot be homologous 

 with, it. A slight notch in the upper margin of the hemi- 

 sphere shows the usual situation of the parieto-occipital 

 sulcus and represents the more dorsal of the two elements 

 which go to form the parieto-occipital sulcus in Man (vide 

 infra). There is a short, plain, collateral sulcus and a calloso- 

 marginal which has no genual element. 0. C. 1337 Ga. 



D. 572. The brain of a Red Howler (Alonatta senicula), 

 (fig. 234). 



Fig. 234. (xf.) 



OLF. BULB. 



SULC. ORB 



. RHIN.F. 



SULC. COLL. 



OLIV. BODY. 



Thiswell-pn-H-rvcd spi-rimm is perfect, in all parts except 

 the olfactory bulbs, which are mining. 



External to the orbital sulcus (which is triradiate on the 



ri-ht and >imply linear on the leli hemisphere) there i.> a 





