192 



PROCEEDINGS OF THE ACADEMY OF 



[1879. 



the internal cusp.is well developed. The heel is shorter than the 

 blades of the crown, and is wide and without tubercles in its some- 

 what worn condition. Its external border rises to an edge. The 

 tubercular is wider than the corresponding tooth in the cotempo- 

 rary species of Canidse, although not so wide as long. Its crown 

 rises in two low tubercles which stand transversely near the middle. 



Measurements. 

 Length of skull to orbit (axial) 

 Depth of skull to orbit (axial) 

 Interobital width .... 

 Width of nares 



Length of superior molar series 

 Length of bases of three premolars 

 Length of base of sectorial 

 Width of sectorial in front 

 Width of first tubercular anteroposterior 

 Width of first tubercular transverse 

 Length of mandible to angle . 

 Elevation at coronoid 

 Elevation at sectorial 

 Length of inferior molar series 

 Length of inferior sectorial 

 Length of heel of inferior sectorial 

 Length of inferior tubercular . 

 Width of inferior tubercular . 



M. 

 .049 

 .042 

 .040 

 .017 

 .038 

 .019 

 .013 

 .009 

 .006 

 .014 

 .093 

 .051 

 .020 

 .045 

 .014 

 .003 

 .006 

 .005 



Tan der Heaven has given 1 descriptions and figures of the 

 skull and dentition of the Icticyon venaticus of Lund, of Brazil. 

 From these it appears that the present species differs from the 

 latter in the greater development of the inner part of the tuber- 

 cular molar of the superior series; in I. venaticus this part is 

 much reduced. The tubercular molar of the lower jaw is also 

 much smaller in the living species, the angular and coronoid pro- 

 cesses less developed, and the condyle less extended transversely. 

 The cranium of the I. crassivultus is much more robust, but not 

 much longer than that of I. venaticus. 



Discovered by J. L. Wortman in the Truckee beds of the White 

 River, Tertiary of the John Day River region of Oregon. 



1 Over het Geslacht Icticyon ; wis. en natuurk. Verb, der Koninkl. 

 Akademie, Amsterdam, Deel. III. 



