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Show 768 PROF. W. H. FLOWER ON MLURUS FULGENS. [Nov. 15, Tbe tooth is also, relatively to the others, much smaller than in the rest of the Carnivora. In the Procyonida? the sectorial has a very broad inner lobe, usually with an anterior and a posterior cusp, and is supported by a distinct third root, median in position as regards the blade. In Mlurus the inner lobe is still larger, having, besides the two cusps, a more internal one upon the cingulum, and is supported by a large antero-median third root. Even the tooth in front of this has a large inner lobe, apparently supported on a third root, which exists in no other carnivore ; but this is in conformity with the general characteristic, viz. great transverse breadth, of the whole molar series. Although the molar teeth of Mlurus, at first sight, appear so different from those of any other carnivore, a close examination shows that they are essentially formed upon the same plan as those of Procyon, the differences arising from the sharper and more pronounced condition of the cusps, and the greater development and cuspidation of the external and, especially, the internal cingulum. These differences are certainly less than many which occur in different genera of other recognized families, the Mustelidee or Viverridce for example ; and it would be difficult to formulate them as family characteristics, especially if the equally aberrant Cercoleptes has to be included in the definition of the Procyonidce. The presence or absence of a bridge of bone on the outer side of the pterygoid plate of the alisphenoid, forming an "alisphenoid canal," through which the external carotid artery passes, has been shown to be remarkably constant in the different minor groups or families of the Carnivora *, all the true Ursidee having this canal, and all known Procyonida? and Mustelidee, without exception, wanting it. Mlurus in this respect agrees with the Ursidee, and is separated from the Procyonidce; and though this character must have some importance, it may fairly be considered questionable whether alone it is sufficient to constitute a family distinction. The exceptional habitat of Mlurus may also be taken into account, all the true Procyonida? being confined to the N e w World ; but although it would be more satisfactory in some respects to find structural characters agreeing with geographical distribution, there are too many cases of the contrary to lay much stress upon this circumstance. Both the nearly allied families Ursidee and Mustelidee are very widely distributed, the latter being almost cosmopolitan ; and there is no a priori reason, except paucity of species, why the Procyonidce should not be so also. Of the general affinities and position of Mlurus, I do not doubt that they are indicated by the place I assigned to it in the diagram of the relations of the existing Carnivora in a former communication (P. Z. S. 1869, p. 37). The only question is whether, as a matter of convenience, we should draw the line which includes the Procyonidce round this Asiatic genus also, or whether, as in that diagram, we should keep Mlurus outside that group, as a member of * See H. N. Turner, P. Z. S. 1848, p. 63; and also W . H. Flower, ibid. 1869, p. 4. |