ANALYSIS OF SUBFAMILIES OF MUSTELID^. 5 



1. Last molar of upper jaw (M t) transverse, (with the inner ledge in- 



flated at its inner angle ;) sectorial tooth with a single inner cusp. 



a. M ^ ; first true molar (sectorial) of lower jaw followed by a second 

 (tubercular) one. Toes short, regularly arched, and with the last 

 phalanges bent up, withdrawing the claws into sheaths. (Gray.) 

 [Martens and Weasels.] Musteline. 



h. M J ; first true molar (sectorial) of lower jaw only developed. Toes 

 straight, with the last phalanges and claws extended ; the latter 

 non-retractile. (Gray.) [Extra-limital.] .... Mellivorin^. 



2. Last molar of upper jaw (Ml) enlarged and more or less extended 



longitudinally.— M J. Toes straight, with the last phalanges and 

 claws extended; the latter non-retractile. (Gray.) [Badgers.] 



Melin^. 



B. Auditory bulla elongated and extending backwards close to the par- 



occipital process. (Flower.) Palate moderately emarginated. 

 1. Last molar of upper jaw (M^) transverse; (with the inner ledge nar- 

 rowed inwards) : sectorial tooth with two inner cusps. [Extra-lim- 

 ital.] Heuctidixje. 



C . Auditory bulla inflated, undivided, with the anterior inferior extremity 



pointed and commonly united to the prolonged hamular process of 

 the pterygoid. (Flower.) Palate moderately emarginated. 

 1. Last inolarof upper jaw (M^) transverse; (with the inner ledge com- 

 pressed.) [Extra-limital.] ZoRiLLiNyE. 



D. Auditory bulla little inflated, transversely constricted behind the 



meatus auditorius externus and thence inwards ; in front flattened 

 forwards ; periotic region expanded outwards and backwards. Pal- 

 ate deeply emarginated. 

 1. Last molar of upper jaw (M^) quadrangular, wide, but with an ex- 

 tended outer incisorial ledge. [Skunks.] .... Mephitin^. 

 II. Skull with the cerebral portion swollen backwards and outwards; 

 and with the rostral portion abbreviated, high and truncated for- 

 wards, and widened and depressed above; anteorbital foramen 

 enlarged and produced downwards and backwards. Feet with 

 well-developed interdigital membrane, and adapted for swimming. 

 [The species highly aquatic, one of them marine.] 



A. Teeth normal, 36 (M i, PM f , C 1, I | X 2) : sectorial tooth (PM 4) 



normal, efficient, with an expanded inner ledge ; the other molars 

 submusteline. Posterior feet with normally long digits. [Otters.] 



Luteins. 



B. Teeth very aberrant, 32 (M i, PM |, C j, I f— the lower inner incisors 



being lost — X 2) : sectorial tooth (PM ^) defunctionalized as such, 

 compressed from before backwards; the other molars also with 

 blunted cusps. Posterior feet with elongated digits. [Sea Otter.] 



Eniiydrinje. 



Of tlie foregoing eight subfamilies, three, namely, the Melli- 

 vorince, Eelictidincv, and ZoriUirue, each of which consists of a 

 single genus, are confined to the Old World. No one of the 

 subfamilies is peculiar to North America ; h\xii\\Q MeiyliitiiuVy 



