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Show 256 PROF. HUXLEY ON THE CRANIAL AND [Apr. 6, TABLE VII.-Proportional Measurements of Teeth and Palate of Canis aureus. I. II. HI. Length of ^ 27 31 33*8 m.i 22 24 21*6 >> >> 2J 12 12*2 13*2 j> » , .. 30*5 34 35*8 " " TO. 1 17 16*9 16*6 " » m. 2 7*5 7*5 » " TO. 3 Length of palate 125 141 143 Breadth of palate .... 94 90 90 The actual dimensions in millimetres are as follows :- TABLE VIII.-Cranial and Dental Measurements of Canis aureus. I. II. III. Lengtb of basicranial axis. . 59 53 53 EUli^ ..„ 16 16*5 18 Vhl ... 13 13 11*5 »J 7 6*5 7*1 -r 18 18 19 " TO. 1 --, 10 9 9 " TO. 2 - 4 4 " m. 3 palate 74 75 76 Breadth of „ 56 48 48 The comparison of these two tables is interesting; for, according to the first, the variations of the dimensions of the teeth in proportion to those of the basicranial axis cover the whole range between Canis azaree and the Wolves ; on the other hand, the second shows that, while the basicranial axis, doubtless following the actual size of the animal, varies considerably, and while the teeth also vary, the two sets of variations do not correspond: hence, in the proportional table, the differences in the sizes of the teeth appear to be greater than they really are. Similar results are attained when the measurements of any considerable number of specimens of other canine skulls are compared. In fact, while in both the Thooid and the Alopecoid series the species may be arranged in a scale characterized by the gradually increasing relative and actual dimensions of the sectorial teeth, each species occupies not a line but a broad zone upon that scale, which zone is overlapped by that of the species below and by that of the species above. 9. The lowest Alopecoids and the lowest Thooids agree in the relatively small size of their sectorial teeth ; and many possess a large lyrate sagittal area and a strongly lobate mandible. The genus |