180 PROCEEDINGS OF THE ACADEMY OF [1879. 



Palaeocyon, Lund. 



Extinct species of South America onty. 



Lycaon, Brooks. 



Existing species of Africa, only known as yet. 



Temnocyon, Cope, Proceedings Amer. Philosophical Society, 1878, p. 68. 



In this genus the heel of the inferior sectorial tooth rises into 

 a single more or less median crest; in Canis the corresponding 

 front is basin-shaped, with tubercles on each side. The superior 

 molars of the typical species, T. altigenis, are unknown, but those 

 of a new species, described below, do not differ from those of the 

 genus Cants. The Cynodictis crassirostris of Filhol, from the 

 French Phosphorites, approaches this genus. 



Temnocyon coryphaeus, sp. nov. 



This is the most abundant dog of the Truckee beds of the 

 John Day country. I have identified it heretofore as my Canis 

 haiishornianus, but I And on examination of the inferior sectorial 

 tooth that it is a species of Temnocyon. This genus was charac- 

 terized by me on evidence furnished by a mandible of a species 

 which I named T. altigenis, 1 which is of considerably larger size 

 than the present one, but which agrees with it in the presence of a 

 cutting edge instead of a basin on the heel of the inferior secto- 

 rial. The C. hartshornianus, known as yet from few fragments, 

 is intermediate in dimensions between these two. 



Several crania, and more or less of the skeleton of the T. cory- 

 phsens, are present in m} r collection. A nearly perfect skull dis- 

 plays the following characters : The orbits are entirely anterior 

 to the vertical line dividing the skull into halves, and the muz- 

 zle is proportionately shortened. It is also narrowed anteriorly, 

 and its median line above is shallowly grooved. The interor- 

 bital region is greatly convex to the supra-orbital region, and is 

 grooved medially. The postorbital processes are mere angles, 

 and are flattened from below. The cranium is much constricted 

 behind the orbits, where its diameter is not greater than the width 

 of the premaxillary incisive border. The sagittal crest is much 

 elevated, and forms a perfectly straight and gradually rising out- 

 line to its junction with the incisor. The borders of the latter 

 are very prominent, extending backwards considerably beyond 



1 Proceedings Amer. Philosopk. Soc, 1878, viii. p. 68. 



