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Show 226 MR. A. H. GARROD ON TOLYPEUTES TRICINCTUS. [Feb. 19, large size of the olfactory lobes1, together with its general proportions, and but little more. Our knowledge of the brain of the Dasypodidse has been much increased by a paper from the pen of Prof. Turner in the first volume of the 'Journal of Anatomy and Physiology'2 on the brain of Dasypus sexcinctus, in which the bibliography of the subject is fully given. The general appearance of the brain of Tolypeutes tricinctus differs but little from that of Dasypus sexcinctus, whilst in surface-markings it much more closely resembles that of Tatusia peba, as figured by Rapp3, being comparatively simple in its gyration. There is not that difference in the breadth of the anterior and posterior portions of the cerebral hemispheres which is found in Dasypus sexcinctus. The Sylvian fissure is only represented by an open and very shallow angle, above which, on the surface of the hemisphere, is a slight, partly encircling, shallow groove of some length, separated from it by a very short distance (vide fig. 2, c). Fig. 2. _ Brain of Tolypeutes tricinctus. The large olfactory lobes are are much broader than they are deep. On the surface of each cerebral hemisphere there are two sulci. One of these, the anterior, is horizontal, and divides the frontal lobe into an upper and a lower part. Its outer extension is nearly to the lateral margin, not going backwards more than one fifth the length of the hemisphere. Internally it ceases on the flat interhemispheral surface as far backward as its outer end (vide fig. 2, a). The second sulcus is upon the superior cerebral surface, running from behind forwards and inwards. Posteriorly it commences at the outer posterior angle of the hemisphere a short distance from its ex- 1 "Les formes cerebrales des Edentates," Nouv. Archiv. du Museum, 1869, torn. v. pl. ii. fig. 8. 2 1867, p. 313. 3 Edenlnten, tab. viii. fig. 3. |