yo Journal of Comparative Neurology. 



its cephalic end it appears to communicate with the cephalic 

 branch of the supersylvian. This appearance will be discussed 

 more fully under the description of the ansate fissure. 



The ectolateral fissure occupies a relatively higher or more 

 dorsal and caudal position than in CallorJumis. It is of a more 

 secondary character and courses approximately parallel with the 

 postsupersylvian. 



The cruciate, unlike that of Callorhiniis, is represented upon 

 both the mesal and dorsal aspects. On the left hemicerebrum 

 a shallow is present in the dorsal portion not far from the mar- 

 gin. No distinct "ursine lozenge" is present here as in Cal- 

 lorhimis. The foreshortened condition of this region may have 

 something to do with its absence. 



A well defined postcruciate fissure is present on the left 

 side. It presents a zygal (Wilder) or quadriradiate form. A 

 slight secondary fissure near the olfactory bulb may represent a 

 rudimentary precruciate fissure. 



The superorbital fissure shows a better development than 

 in Callorhinus and similarly has no connection with the rhinal. 

 But the opposite end, dissimilarly, extends farther and is over- 

 lapped by the olfactory bulb. 



The medilateral is not present in PJioca as a distinct fissure. 

 Its location is occupied by a series of short disconnected fis- 

 sures. 



The coronal fissure is a relatively longer fissure than in Cal- 

 lorhinus but is not so entirely disconnected from adjacent fis- 

 sures. Its dorsal end lies caudal to the cruciate. On the left 

 hemicerebrum it is separated by a shallow from an apparent 

 connection with a continuation of the cephalic branch of the 

 supersylvian. On the right hemicerebrum the shallow is sug- 

 gested by the interlocking at this point of two submerged but- 

 tresses. 



The ansate fissure, while not distinctly represented as an 

 independent fissure, would, it seems to me, be indicated by the 

 fissure extending from the coronal to the cephalic branch of the 

 supersylvian, where, on each hemicerebrum, the interlocking of 

 submerged buttresses would again suggest a shallow shutting it 



