266 PHYSIOLOGICAL SERIES. 



D. 331. The brain of Canis rudis. 



D. 332. The brain of a Japanese Raccoon-Dog (iY//r/r /,///,> 

 procyonoides) , ( ? ) . 



Note again how the ectolateral sulcus takes the place of 

 the postlateral, which is absent. 0. C. 1325 L c. 



D. 333. The brain of a Japanese Raccoon-Dog (Nyctereutes 

 procyonoides), (<$}. 0. C. 1325 L b. 



D. 334. The brain of a Cape Hunting Dog (Lycaon pictus) , ( $ ). 



0.0. 1325 La. 



Section ARCTOIDEA. 

 Family PROCYONID^E. 



D. 335. The brain of a Raccoon (Procyon lotor). 0. 0. 1325 R a*. 



Presented by St. George Mivart, / . 



D. 336. The brain of a Raccoon (Procyon lotor). 0. C. 1325 R. 



D. 337. The brain of a Raccoon (Procyon lotor}. 



It is distinctive of the Arctoid section of the Garni vora 

 that the " Sylvian fissure" is very long and deep, and that 

 the first arcuate gyrus has become wholly engulfed in ihi> 

 great cleft so that the lips of the "fissure" are formed by 

 the second arcuate gyrus, and not by the first gyrus a- in 

 the Cynoid section ; and a precrucial sulcus make- its ap- 

 pearance, even in many of the smallest members, so as to 

 mark off the area which Mivart has called the " Ursine 

 Lozenge." (( 'omparo fig. 155.) 



The crucial sulcu- is long, very deep, and placed ob- 

 liquely, ami is usually quite independent of the intercalary 

 (the cephalic part of the -plenial) sulcus. There are no 

 preerueial sulei in one (D. 335) of these specimen-, in 

 another (D. 33(1) they are faintly, whilst in the third they 

 are well-developed. 



A comparison of the<e three brains shows the great 

 variations in the coronal, lateral, ansate, and postlateral sulei 

 which may occur in one Bpecies. In one brain (I). ;;.",r,) 



