390 PROCEEDINGS OF THE ACADEMY OF [1896. 



No. 2 ; both mandibular rami. m. m. 



Length of premolar series ; 1 1 



Length of molar series; 13.5 



Diameters M. y | f "teroposterior ; 10 



* ( transverse of heel. 3 



Diameters M.^ j anteroposterior ; 3.5 



^ I transverse ; 2.5 



Depth of ramus at Pm. 1 ; 9 



Depth of ramus at Pm. 2 ; 10 



No. 3 ; smallest ramus. 

 Length of last three molars ; 17 



Length of M. -j- ; 9.5 



Depth of ramus at Pm. 1 ; 6 



Depth of ramus at M. 2 ; ' 8 



In two last superior molars the short angle connecting the 

 metaconule with the paraconular crest is rudimental or wanting, so 

 that the arrangement only differs from that of iV. /ossic?e/is in the 

 greater separation of the metaconule from the crest. Such teeth 

 are nearly transitional between the two species, but they maintain 

 the inferior size of M. orthostichiis. The two types of molars 

 might be regarded as representing male and female, but for the 

 difference in the relations of the inferior premolars, as pointed out 

 in the analytical table of species. 

 Pelyciotis lobulatus, gen. et sp. nov. 



Char. gen. — Dental formula Pm. ^, M. ^. Sectorial with basin- 

 shaped heel, and without metaconid. Premolars without posterior 

 lobe. 



The genus Pehjcictis is only known from the mandible. The 

 dentition agrees in number of teeth with both Mephitis and Puto- 

 rius. From the former it differs in the absence of metaconid, and 

 from the latter in the basin-shaped heel of the sectorial molar. 

 From Gulo it differs in the presence of but three premolars. But 

 one species is known, P. lobulatus Cope, represented by an entire 

 left mandibular ramus containing all the teeth excepting the third 

 premolar and the incisors. 



Char, specif. — This weasel is larger than any of the existing 

 species of Putorius of North America, but equals P. vittatus of 

 Brazil. In some respects the parts preserved resemble the corre- 

 sponding ones of Mephitis orthostichiis, but the differences are also 

 conspicuous. The ramus is rather robust, and the symphysis is 

 short. The inferior border is regularly convex, and rises to the 



