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Show 1880.] DENTAL CHARACTERS OF T H E CANIDJE. 285 group, to the Wolves, Lycaons, Cyons, and Northern Foxes, as tbe most modified forms. II. In the skull these modifications consist chiefly (a) in the increase of absolute size; (b) in the increase of the relative dimensions of the jaws, and particularly in the width of the palate; (c) in the persistence or disappearance of the sagittal area common to all young Canidae, and the correlative development or absence of a sagittal crest; (d) in the diminution of the inflexion of the angular process of the mandible; (e) in the disappearance of the subangular lobe. III. In the teeth, the most important modifications are the increase in the proportional size of the sectorials, accompanied by the relative diminution and, in some cases, suppression of the posterior molars. In Otocyon, -- has usually disappeared. In C. cancrivorus, -'--, -1-, and jjp-j are most frequently suppressed; but - 7 often remains, and ^- persists in one known case. In the great majority of the Canidae, - , - , and ^-j are normally suppressed, while -^ becomes relatively small, and, as a rule, disappears'in Cyon. Finally, in the majority of examples oi Icticyon, both - and -^ are wanting, and when - is present it is very small. The gradation will be rendered more intelligible by placing the formulae of the cheek-teeth under one another. Maxilla. Mandible. pm. m. pm. m. Otocyon: , ' > , ' > ( ' 1 , ' , Fullest dentition observed... 1 2 3 4 1 2 3 4 1234 1 2 34 Ordinary 12 3 4 1 2 3 * 1234 1 2 34 C. cancrivorus: Fullest dentition observed... 1 2 3 4 1 2 3 * 1234 1 2 34 Ordinary 12 3 4 1 2 * * 1234 1 2 3* Most Alopecoids and Thooids 1234 12** 1234 123* Cyon 1234 12** 1234 12** Icticyon: Fullest dentition observed... 1 2 3 4 1 2 * * 1 2 3 4 1 2 * * Ordinary 1234 1 * * * 1 2 3 4 1 2 * * In the individual teeth, the most important changes are the increase of the length in proportion to the breadth of the upper sectorial, and in the lower sectorial, the change in the relative dimensions and position of the inner anterior cusp, which, from being on a level with the outer and higher than it in Otocyon, becomes smaller and shifts further and further backwards, eventually even disappearing, as in |