6 MR. ST. GEORGE MIYARX ON THE 



gyrus thus formed has its pre-Sylvian limb sometimes much 

 broader, sometimes narrower thau that behind the Sylvian fissure, 

 and it is more or less vertically grooved, the groove being a rem- 

 nant of that sulcus in the Dog which separates its first and 

 second Sylvian gyri one from the other. The gyrus next above 

 the parietal gyrus (answering to the third from the Sylvian fissure 

 of the Dog) is simple, and not only differs from the correspond- 

 ing gyrus of the Dog in being undivided, but also in being shorter, 

 the sulcus between it and the sagittal gyrus not extending so 

 far backwards. The hippocampal gyrus is separated ofi* from the 

 sagittal by the continuation forwards and upwards of the calloso- 

 marginal sulcus, as in the Dogs. The most striking diff"erenee 

 presented by the upper surface of the Civet's cerebrum, when 

 compared with the cerebrum of any of the Carnivora here 

 before referred to, is the minute size of the crucial sulcus — a 

 sulcus so conspicuous in all the Felidae and Canida?. It is with 

 this minute crucial sulcus that the calloso-marginal sulcus 

 unites. 



Genetta. — The Grenet's * brain is like that of the Civet, still 

 further simplified. It agrees with the latter save that the 

 Sylvian gyrus shows less traces of its subdivision into two circum- 

 Sylvian gyri than in the Cats (the single Sylvian gyrus being 

 almost smooth), and that the crucial sulcus is much more rudi- 

 mentary still, being only indicated, on the dorsal surface of the 

 cerebrum, by a minute notch. 



Nandinia. — The brain of this exceptional form f is quite like 

 that of Genetta, save that the Sylvian gyrus more resembles the 

 same part in Viverra. 



JParadoxurus. — The brain of the palm-Cats % has the hinder 

 limb of the Sylvian gyrus twice the size of its anterior limb, and 

 marked by a vertical groove, which indicates that both the first 

 and second of the Sylvian gyri of the Dog are represented behind 

 the Sylvian fissure, while only one of these canine gyri is repre- 

 sented in front of it. As in the Civet and Grenet, the hinder part 

 of the parietal gyrus is short, blending posteriorly and inferiorly 

 with the sagittal gyrus behind the hinder end of the shortened 



* See Leui-et, I. c. p. 381 ; P. Gervais, p. 128, plate vii. fig. 6. See also P. Z. S. 

 1882, pp. 515 & 516, fig. 11 ; Kriieg, I. c. plate xxxvi. 



t As to its peculiarities, see P. Z. S. 1882, p. 169. 



\ See P. Gervais, I. c. p. 129, plate ix. figs. 2, 2a, 26, & 2c; and Krueg, l. c. 

 plate xxxvi. 



