MUSTtiUILK. 15 



b. The Dentition. 



Must i« la. — Dental formula — i. f, c. \, pm. |-f, m. !. 



Permanent Dentition of the Upper Jaw. — L 1 and 2 are very small, one-rooted, 

 simple teeth, i. 3 is a larger and caniniform tooth. The canine is a relatively 



very large tooth with a long slightly recurved crown. I'm. 1 is a very small one- 

 rooted tooth which, while present in Mustela martes and other representatives of 

 the genus Martes of Nilsson, is absent in M. putorius, M. vobusta, M. erminea and 

 M. vulgaris, representatives of the genus Putorius of Nilsson. Pm. 2 and 3 are 

 simple conical teeth with two roots and a rather well-marked cingulum. Pm. 4, 

 the carnassial, is a large tooth with a prominent blade consisting of a larger 

 anterior and a smaller posterior lobe. The cingulum is well developed, and there 

 is a prominent inner tubercle near the anterior border of the tooth. ]\I. 1, which 

 is as large a tooth as pm. 4, is short, but very wide, with a raised outer portion 

 bearing several small, ill-defined cusps, and a depressed and more flattened inner 

 portion terminated by a raised semicircular inner border. 



Permanent Dentition of the Lower Jaw. — I. 1, 2 and 3 are all very small teeth, 

 their crowns being only from a quarter to a third as long as that of the canine, 

 which is somewhat sharply recurved. Pm. 1 is a small, simple, one-rooted tooth, 

 and like pm. 1, is absent in Putorius. Pm. 2, 3 and 4 are all very similar teeth 

 with two roots and conical crowns. In pm. 3, and still more in pm. 4, there are 

 indications of a slight additional cusp on the posterior edge of the main cusp. 

 M. 1 is a large tooth with a bilobed trenchant blade and a depressed posterior 

 portion or talon only half the length of the blade. M. 2 is a small one-rooted 

 tooth with a rounded crown. 



GrULO. — Dental formula — i. f, c. \. pm 



45 



m. t- 



Permanent Dentition of the Upper Jaw. — I. 1 and 2 are relatively powerful 

 teeth, rather sharply curved downwards, with edges of a somewhat chisel-shaped 

 character and indications of slight lateral cusps. I. 3 is a large caniniform tooth with 

 a strongly marked cingulum, which passes obliquely along the inner face of the tooth, 

 ending in a slight cusp not far from the point. C. is of the usual character, and 

 powerful, but not specially large. Pm. 1 is a simple, conical, one-rooted tooth. 

 Pm. 2 is two-rooted, and has the apex of the crown placed far forward. Pm. 3 

 is a very powerful two-rooted tooth with a rather low conical crown. Pm. 4, the 

 carnassial, is a large tooth with a prominent bilobed blade supported by two 

 roots, the anterior lobe being the larger. The inner tubercle, which is supported 

 by a third root, is small and depressed, but very sharply marked off from the rest 

 of the tooth. There is a fairly prominent cingulum which is raised into a slight- 

 cusp at the anterior end of the tooth. M. 1 is a rather large tooth transversely 

 placed. A depression divides it into an outer portion supported by two roots and 



