330 PHYSIOLOGICAL SERIES. 



The great vertical pseudosylvian sulcus (s) is formed by 

 the meeting of the vertical parts of the two ectosylvian sulci, 

 which diverge below to form a horizontal sulcus parallel 

 to the rhinal fissure. The anterior ectosylvian sulcus is 

 prolonged forward as a paraorbital sulcus, which overlaps the 

 true orbital sulcus. 



The suprasylvian arc surmounts the pseudosylvian 

 sulcus, and is then prolonged back to the posterior margin 

 of the hemisphere. The anterior part of the suprasylvian 

 arc is joined to the coronal sulcus. 



There is no proper postsylvian sulcus, but the great 

 quadrilateral area between the suprasylvian sulcus and the 

 posterior rhinal fissure is broken up by an irregular series 

 of sulci. 



There is a characteristic arrangement of lateral, ((to- 

 lateral, and entolateral sulci (fig. 191). 



0. C. 1328 Ed. 

 Presented by Sir Victor Brooke^ JJar/. 



D 441. A cast of the cranial cavity of an extinct Irish Deer 

 (Cervus yiyantcus). 



D. 442. The brain of a Reindeer (Ranyifer tarandus), three 

 weeks old. 



This small specimen of the Reindeer's brain resembles 

 such brains as that of Odocoileus, especially in the pre- 

 sylvian region, more closely than the succeeding specimens. 



The diagonal sulcus is quite independent of the supra- 

 sylvian sulcus. 0. C. 1328 E h. 



D. 443. The brain of a Reindeer (Ranyifer taramlus), ( ? ). 



This is a highly complicated Deer's brain. If we imagine 

 the progressive series of changes which are to be noted in 

 a successive comparison of the brains <!' ////<//<>/ W,\, /'//(///. 

 Capreolus, and Odocoileux to be carried a step I'urlher. an 

 accurate conception of the Reindeer's brain will be gained. 



0. C. 1328 E^r. 

 Holl, Archiv f. Anat. 1000, p. 318. 



D. 444. The brain of a Reindeer (Ranyifer tarandus). 



This resembles D. 442, but is considerably larger. 



O.C 13 





