MTSTELHXZE. L3 



rare cases the molars mav number \ or §. The upper carnassial, pm. 4, differs 

 from that in Ursidae and resembles that in Felidse, Hysenidae, and Canidse, in 



possessing - a more or less antero-mternally placed inner tubercle supported by a 

 distinct root. 



a. The Skull. 



Mustela. — The cranial portion of the skull is not so sharply marked off from 

 the facial as in Meles and Lntra. The sagittal and superciliary crests arc less 

 developed than in Meles; the occipital crest on the other hand is commonly very 

 strong. The post-orbital processes of the frontal and jugal are fairly prominent, 

 and sometimes approach one another, especially in Mustela erminea. The foramen 

 magnum is of relatively large size. The auditory bulla is considerably inflated. 

 The infra-orbital foramen is smaller in proportion to the size of the cranium than 

 in Lntra and Meles, and the post-glenoid process is not sufficiently recurved to 

 hold the mandible attached to the cranium. 



Gulo. — The cranial portion of the skull is more strongly marked off from the 

 facial than in Mustela, but less so than in Lutra. There is a greater development 

 of ridges, especially of the sagittal crest, than in any other British member of the 

 Mustelidas, except Meles. The jaws are very powerful. The foramen magnum 

 is of relatively smaller size than in Mustela, and the auditory bulla, though 

 variable, is less inflated. The paroccipital process of the exoccipital is prominent, 

 while the post-orbital process of the jugal is very slightly developed. The post- 

 glenoid process is much incurved, and holds the mandible firmly attached to the 

 cranium. 



Meles. — The skull of the common badger bears a very close resemblance to that 

 of the glutton in general form, development of ridges, strength of jaAvs, and 

 relative size of the foramen magnum. Also in the development of the paroccipital 

 process of the exoccipital and of the post-glenoid process, which attaches the 

 mandible to the cranium perhaps even more firmly than in Gulo. The superciliary 

 ridges are somewhat stronger than in Gulo, and the zygomatic arch is rather 

 stouter. 



Lutra. — The skull of the otter is of a peculiar character, broad and depressed, 

 with the cranial portion, which is much expanded posteriorly, sharply marked off 

 from the facial portion by a strong constriction behind the orbits. The sagittal 

 and superciliary ridges are but slightly developed. The infra-orbital foramen is 

 very large, and the post-glenoid process is not so much recurved as in Meles. The 

 ventral surface of the cranial portion of the skull is notably broad and flattened, 

 and the auditory bulla is very little inflated. The mandible is small and weak in 

 comparison with that of Meles. 



