. On the anatomy of vertebrates [electronic resource] . a little way upon thehemisphere in the Cavies, as in the Wombat. In the Por-cupine the sylvian fissure, figs. 77, 84, 5, is well marked,though short, and there is a feeble indication of the coronalfissure, 12. In the smaller and especially the insectivorous Bruta thebrain presents the lissencephalous type, having smooth, low,triangular hemispheres, leaving the mesencephalon as well asepencephalon in view posteriorly. Dasypus has the fore partless contracted than Myrmecophaga, at least than M. Bradypus the anterior expansion g
. On the anatomy of vertebrates [electronic resource] . a little way upon thehemisphere in the Cavies, as in the Wombat. In the Por-cupine the sylvian fissure, figs. 77, 84, 5, is well marked,though short, and there is a feeble indication of the coronalfissure, 12. In the smaller and especially the insectivorous Bruta thebrain presents the lissencephalous type, having smooth, low,triangular hemispheres, leaving the mesencephalon as well asepencephalon in view posteriorly. Dasypus has the fore partless contracted than Myrmecophaga, at least than M. Bradypus the anterior expansion gives an ovate form to thehemispheres; and now, besides the hippocampal, callosal, ecto-rhinal, and sylvian fissures, the upper surface shows the medi-lateral, suprasylvian, and frontal ones. The medilateral bendsoutward anteriorly, defining the fanterior lobe impressed bythe short angular or triradiate 6 frontal fissure. The abovefissures mark out a medial, lateral, sylvian, postfrontal, andprefrontal convolutions. On the inner surface a supercallosal. PROSENCEPHALON OF MAMMALS. Ill fissure now defines a convolution of the corpus callosum,1 thelower margin of which, resting on that body, is thec labium cerebriof anthropotomy : in Sloths, as in Shrews and Rodents, it is an-terior to and distinct from the ( hippocampal fissure and fold. In all Lissencepliala the hemispheres present the followingstructure, the rise in which, as compared with that in Lyence-phala, is independent of the smallness and smoothness of thosedivisions of the brain. Taking that of the Beaver ( Castor fiber), e. g., and comparingits prosencephalon with the sub-convolute one in Phascolomys orMacropus, we find, on divaricating the hemispheres, that the6 corpus callosum is brought into view, and on removing thecerebral substance to a level with this body, as in fig. 78, itsfibres are observed to diverge into the substance of each hemi-sphere, some bending upward, but a greater proportion archingdownward and co
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