CEUEBEAL COKTOLTJTIOlSrS OF THE CAElSriTOEA.. 13 



generally, as miglit be expected, to show a resemblance to the 

 brains of JProcyon and Nasua, thougb it is less convoluted. It 

 shows a long Sylvian fissure embraced by a simple Sylvian gyrus. 



By the kindness of Professor Flower and Dr. Giinther I have 

 been enabled myself to obtain a cast of the interior of the skull 

 of this animal, which cast I have deposited in the British Museum, 

 South Kensington. Unfortunately it shows but little of the 

 convolutions, but the size and forward position of the crucial 

 sulcus agree with Grervais's figure. There is no positive indi- 

 cation, that I can perceive, of an " Ursine lozenge," though there 

 is no evidence against its presence, the part being indistinct. 

 The sagittal gyrus is exceedingly wide, and complicated by a 

 median longitudinal groove. 



Bassaricyon. — It is again through the kindness of Professor 

 Plower and Dr. Giinther that I am enabled to contribute any notes 

 as to the cerebral form of this species. It is as yet entirely 

 unknown ; but I have been allowed to take a cast from the in- 

 terior of the skull, which cast I have also presented to the 

 British Museum. By it, it seems that there is a very large 

 crucial sulcus, not placed so far forwards as in JBassaris. On one 

 side there is a distinct indication of the presence of an " Ursine 

 lozenge." The sagittal gyrus seems to be very broad, but the 

 indications are unfortunately very indistinct. There is an 

 appearance which seems to show that the anterior limb of the 

 Sylvian gyrus is narrower than its posterior limb. 



Cercoleptes. — The brain of the Kiukajou * is short and some- 

 what rounded. Its sagittal gyrus is very wide, and tends to 

 subdivide longitudinally. The parietal gyrus broadens out much 

 anteriorly. The Sylvian fissure is long and oblique, and its 

 embracing Sylvian gyrus has its anterior limb a little narrower 

 than its posterior limb. Professor Grervais says that he found 

 no "plis de passage;" but I find abridging convolution anteriorly, 

 on each side, between the parietal and sagittal gyri. The crucial 

 sulcus is very large, and sends inwards, on either side, a rather 

 faintly marked secondary sulcus, by which a large " Ursine 

 lozenge " is distinctly, though not strongly, defined. The crucial 

 sulcus is joined by the anterior end of the calloso-marginal 

 sulcus, thus cutting off the hippocampal gyrus from the sagittal 

 one f. 



* See P. Geryais, I. c. p. 141, pi. ix. fig. 3; and Krueg, I. c. pi. xxxvii. 

 t See Leuret, I. c. p, 381 ; and P. Gervais, p. 144, pi. ix. fig. 6. 



