E. S. Riggs — Skull of Amphictis. 



259 



by it. The posterior palatine foramina appear just back of the 

 maxillo-palatine suture. 



The occiput is nearly perpendicular. The lambeloidal ridges 

 are prominent only at the inion. There is no sagittal crest ; 

 the linea semicircularis are only slightly marked and do not 

 unite until they reach the occiput, enclosing a narrow sagittal 

 area. The cranium is expanded, showing a large and well-con- 

 voluted brain. 



The frontal region is concave along the median suture ; the 

 nasals are narrow and slender as in the civets. The post-orbital 

 processes are only slight, but back of them there is a marked 

 notch-like constriction. 



The measurements are as follows : 



Length of skull from incisors to condyles 



Breadth across mastoid processes 



Height of occiput above condyles _. 



Glenoid cavity to incisors 



Breadth across post-orbital processes 



Occiput to incisors 



Incisors to last molar 



Length of molar dentition 



Breadth of incisor dentition 



Breadth across first molars 



Length of base of sectorial 



Breadth " " 



Length of base of first molar 



Breadth " " 



Greatest breadth of nasals anteriorly 



Breadth of nasals at middle ... 



M. 

 •074 

 •031 

 •021 

 •054 

 •019 

 •076 

 •085 

 •026 

 •008 

 •027 

 •008 

 •0055 

 •006 

 •0085 

 •007 

 •004 



It will be seen that Amphictis, though by no means a primi- 

 tive form, has many characters in common with both Mustel- 

 idae and the Vineridse. The general proportions of the skull 

 are musteline. The structure of the inner ear, and of the par- 

 occipital and mastoid processes are essentially characteristic of 

 that group, as are also the presence of the glenoid, and the dis- 

 tinct condylar foramina. But on the other hand the short and 

 expanded auditory meatus, the inter-sagittal space, the charac- 

 ter of the molars, and the presence of the alisphenoid canal 

 ally it to the viverines. Thus the genus forms a connecting 

 link between the two families and furnishes further evidence 

 in support of Schlosser's theory that they are of common 

 origin.* 



*Die Lemuren, Chiropteren, etc., de europaischen Tertiars, p. 107. 

 Princeton University. 



