137 



garis) and the more typical Mustelidm. The false molars in the 



3—3 

 4—4' 



O Q 



Weasels (Mustela) are typically rrj, but in some species they are 



reduced to ^~^. As in the FelidcB, the angle of the lower jaw, in the 



greater portion of the MustelidcB, is on the same plane as the lower 

 edge of the horizontal ramus : in other Carnivora it is raised. In this 

 family there is a great tendency in the glenoid cavity of the temporal 

 bone to enclose the condyle of the lower jaw. The condyle is more 

 truly cylindrical, and longer than in other Carnivora. In the Dogs 

 there is no trace of the anterior descending process of the temporal 

 bone, which in the Mustelas confines the condyle of the lower jaw ; 

 in other Carnivora there is always a slight trace of this process, but 

 in none does it enclose the condyles, as in most of the Mustelidce. 



The genera contained in this family are Mustela, Zorilla, Galictis, 

 Bell (which must not be confounded with the Galictis of Is. Geoffrey 

 St. Hilaire, published in the ' Comptes Rendus' for October 1837, 

 p. 581.), Mellivora, Ursitaxus, Helictis and Gido, in which the true 

 molar of the upper jaw is transverse ; Lutra and Mephitis, in which 

 this tooth approaches more or less to a square form ; Taxidea, in 

 which it is triangular ; and lastly, Meles, Arctonyx and Mydaus, in 

 which the true molar is longer than broad. This last-mentioned ge- 

 nus evinces an approach to the order Insectivora. 



Iti the Ursidce there are two well-developed true molars on either 

 side of each jaw : the ' carnassiere' here has changed its function, not 

 being suited, as in other Carnivora, to cutting flesh. The palate is 

 considerably elongated. In the Bears ( Ursus and its subgenera) it 

 is small, being robbed as it were of its nutriment by the true molars, 

 which are very large. In the other Ursidce (Procyon, Nasua, Cer- 

 coleptes, Arctictis and Ailurus,) the ' carnassiere,' especially that of 

 the upper jaw, and the true molars, are nearly equal in size, and also 

 nearly resemble each other in other respects f. 



In the true Bears the form of the lower jaw differs from that of 

 any of the preceding Carnivora in having a projecting process on 

 the under side of the ramus, and situated a little in advance of the 

 angle of the jaw. The same character is also found in many Seals 

 (PhoddcB), which in several other respects appegj to approach the 

 Bears. 



t " From an examination of the external characters of Smserit asfuta, 

 it appears to me that it belongs to this group.'' 



