58 



carotid canal distinct, and more or less in advance of the foramen lacerum 

 posticum; condyloid foramen also distinct from the foramen laceruui 

 posticum ; glenoid foramen generally well defined. Os penis very large. 

 Cowper's glands not developed. (Arctoidea.) 



A. True molars of upper jaw one (M J ; rarely in Mellivorincc i) ; 

 last pre-molar of upper jaw sectorial (rarely in Enhydrince with blunt 

 tubercles). (Arctoidea musteliformia.) 



MUSTELIDAE. (XVI.) 



B. True molars of upper jaw two ; last pre-molar of upper jaw tubercular 

 (rarely in Bassarididce sectorial) . 



1. Last molar of upper jaw oblong and exceeding the first: three true 

 molars in lower jaw ; first narrowest but longest; second oblong and 

 broader. Foramen lacerum posticum introrse, behind the postero- 

 iuternal angle of the tympanic bone; carotid canal little in advance 

 of the foramen lacerum posticum. Tail rudimentary. (Arctoidea 



typica.} 



UKSIDAE. (XVII.) 



2. Last molar of upper jaw more or less transverse and compressed 

 forwards; two true molars in lower jaw; first broadest. Foramen 

 lacerum posticum antrorse from postero-internal angle of the tympanic 

 bone ; carotid canal nearly at or in advance of middle of inner wall 

 of the auditory bulla. Tail well developed. (Arctoidea procyoni- 

 formia.) 



a. Alisphenoid canal developed : auditory bulla very small, and with 

 a very prolonged bony floor to the auditory meatus : paroccipital 

 process long and trigonal, standing backwards and outwards, quite 

 unconnected with the bulla. (Flower.) Teeth 36 (M f, PM -f, C , 



I |X2). 



AELTJKIDAE. (XVIII.) 



b. Alisphenoid canal none : auditory bulla well developed, and with 

 a short bony floor to the auditory meatus : paroccipital process 

 short and blunt, somewhat hooked, generally contiguous to the 

 bulla at the base. 



b. 1. Teeth 36 (M f, PM f, C i, I |X2) ; last pre-molar of upper 

 jaw and first molar of lower tubercular. Snout abbreviated, de- 

 curved. Lower jaw very stout, with an extensive auchylosed 

 symphysis, with high coronoid processes, and extended back- 

 wards and downwards at the angles. 



CEKCOLEPTIDAE. (XIX.) 



b. 2. Teeth 40 (M f, PM f , C j, I |X2); last pre-molar of upper 

 jaw and first molar of lower tubercular. Lower jaw moderate or 

 slender, with a reduced symphysis, with recurved coronoid pro- 

 cesses, and extended upwards to the angles, which are near the 



condyles. 



PKOCYONIDAE. (XX.) 



