EXTERNAL CUAUACTERS OF THE MUSTELIDj^. 811 



The genera may be grouped as follows by the rhinarium : — 



a. No complete and true pliiltrum resembling tlie vest of tlie 

 rliinarium in texture dividing the upper lip, which is at most 

 grooved. 



h. Upper lip divided hy a complete groove of smooth naked 



skin, giving moljilitj' to the right and left halves Gulo, Jlartes. 



h'. Groove on upper lip obliterated or nearly so, the two halves 

 of the lip not separately' movable, or onlj^ slightly so. 



c. Infranarial portion of rhinarium much sliallower beneath 

 lateral slits of nostrils than above them. 



d. Infranarial portion laterally very narrow 3Iustela, Gale, Futorius, 



Charronia, Grison, Ta.videa. 



d'. Infranarial portion laterally moderatelj' deep... Tai/rrt, Ictonyx, Sjpilo- 



gale, Mephitis, Conepattis. 



c'. Infranarial portion very deep beneath lateral slits, 



appro.ximatelj' as deep as portion above them Meles, MeJogale. 



a'. A long narrow phijtrum, resembling the rest of the rhinarium, 

 dividing the upper lip; infranarial portions everj'where very 

 deep Mydaus. 



The Facial Vihrissce. 



The number of tufts of facial vibrissae characteristic of the 

 Carnivora is typically present in the Mustehdae ; but the vibrissse 

 themselves are longer and more numerous in predatory forms 

 (like llartes, Miostela, and Ictonyx) than in fossorial forms (like 

 Mellivora, Meles, and Mejyhitis). They are especially well 

 developed in the matter of rigidity and number in the truly 

 semi-aquatic genera like Latra and Amhlonyx ; but in the 

 tropical West- African Otter, Paraonyx, Hinton records the com- 

 plete absence of the superciliary and upper genal tufts. In other 

 genera, like Meles, the upper genal tuft is sometimes a^^parently 

 absent ; but a noticeable point about this tuft in all genera, 

 when it is present, is its high position on the cheek, only a little 

 below aiid behind the posterior corner of the eye. In the one 

 fresh example of Tayra harhara examined, I could find no trace 

 of the interramal tuft. (Text-figs. 27-29.) 



In Melogale personata the vibrissse are all long and numerous as 

 in predatory forms, the submentals being unusually well developed 

 on the area of nearly naked skin which runs along the lower lip 

 as far as the angle of the mouth, corresponding to that of the 

 upper lip. (Text-fig. 30, G.) 



The External Ear. 



The external ear shows every grade between high specialisation, 

 the primitive condition, and almost complete degeneration. In 

 its highest types, as exemplified by Martes * and Charronia, it is 

 of tolerably large size and is provided with a well-developed bursa, 

 the posterior flap of which is lai'ge, has a strongly convex margin, 

 and is attached above behind the straight-edged portion of the 



* See my paper on the Pine and Beech-Martens (P. Z. S. 1914, pp. 1062-1068). 



