16 



MK. ST. GEORGE MIVAUT ON THE 



Fig. 4. 



P; So. 



Fig. 5. 



Fig. 4. Dorsal surface of brain of Galictis, natiu-al size. C. Crucial sulcus. 



P. Parietal gyrus, ^c. Precrucial sulcus. 8. Sylvian gyrus. 8a, 



Sagittal gyrus. 8f. Sylvian fissure. 



Fig. 5. Lateral view of brain of Galictis, natural size. C. Crucial sulcus. 



P. Parietal gyrus, pc. Precrucial sulcus. 8. Sylvian gyrus. 8a, 



Sagittal gyrus. 8f. Sylvian fissure. 



Grisonia *. — The brain of the Grison is so different from that 

 of the Tayra (^Galictis) as to constitute an argument of some 

 weight in favour of the distinctness of the two genera. In that 

 of the G-rison, the hippocampal gyrus is cut off from the sagittal 

 gyrus by the junction of the calloso-marginal and crucial sulci. 

 There is also a much larger proportional part of cerebrum in 

 front of the crucial sulcus in Grisonia than is the case in Galictis. 

 The sagittal gyrus is very wide, and blends anteriorly with the 

 parietal gyrus. The Sylvian gyrus is oblique and rather short. 



The crucial sulcus is well developed, and an " Ursine lozenge " 

 is more or less distinctly defined in front of it. 



* Or Galictis vittata. 



