CERE13KAL CONYOLL'TIONS OP THE CAUNIVORA. 11 



case in tlie brain of P. caticrivoncs, where there are two or three 

 bridging convolutions, on each side, between the parietal and 

 sagittal gyri. In Procyon we find once more what we have 

 found hitherto only in the Felidse, namely, a continuation of 

 the hippocampal gyrus upwards into the sagittar gyi'us, behind 

 the crucial sulcus, the calloso-marginal sulcus not being con- 

 tinued forwards with the latter. The crucial sulcus is very large 

 and distinct, and presents a character which I have not found 

 to exist in the brain of any non-Arctoid Carnivore. From 

 the anterior margin of the crucial sulcus of either hemisphere 

 a secondary sulcus diverges forwards and inwards, and thus 

 the proximal parts of the two halves of the great crucial sulcus, 

 together with the secondary and anteriorly approximating sulci, 

 form altogether a lozenge-shaped patch, of brain- sub stance which 

 is sufficiently conspicuous. 



The Sylvian fissure is very elongate and very oblique. 



JVastia. — The brain of the Coati * is mainly like that o£ the 

 Raccoon ; but the part in front of the large crucial sulcus is re- 

 latively more extensive, and the sagittal gyrus is larger and more 

 complicated with grooves and depressions. One great difference, 

 however, between the two brains is the small size in Nasim of tlie 



Vertical median section of cerebrum oi Nama riifa, na.t. size. 



G. Crucial sulcus. Cm. Calloso-marginal sulcus. H^. Hippocampal 



gyrus. Sa. Sagittal gyrus. 



lozenge-shaped patch of brain-substance in front of the crucial 

 sulcus. The fact that minute secondary sulci do converge for- 

 wards from the crucial sulcus, I have been careful to verify by a 

 special examination of a brain freshly extracted for the purpose. 



* See Leuret, L c. p. 381, pi. yi. ; and P. Gervais, l. c. p. 140, pi. is. fig. 10; 

 also Krueg, I. c. pi. xxxvii. 



