Merriam.J 



Pliocene and Quaternary Canidae. 



279 



without accessory tubercles. Mr massive; protocouid and para- 

 conid forming a heavy shear, metaconid absent; heel short, with 

 reduced hypoconid and entoconid. Mi and Ms small. 



Occurrence . — The type specimen of this species consists of a 

 mandible (No. M8139, Univ. Calif. Palaeont. Mus.) found at 

 Asphalto, Kern County, close to the foot of the Temblor Range. 

 It was presented to the University by Mr. Bernard Bienenfeld 

 of San Francisco. 



The excavations at the locality where the jaw was found seem 

 to have been in beds ranging from late Miocene to Quaternary, 

 but principally in the latest formation. A jaw of a large species 

 of Smilodon associated with the Hyaenognathus mandible indicates 

 that it was probably obtained from a Quaternary bed, or possibly 

 from the late Pliocene. 



Mandible. — The lower jaw is short and heavy, having a strong 

 resemblance to that of the hyaena. Below the molars its height 

 and thickness are about equal to that in the hyaena, but the 

 anterior portion below the premolars is somewhat higher and 

 heavier. As in the hyaena, the inferior border of the mandible 

 is strongly convex below the posterior end of the molar series. 



Owing to the extreme shortness of the jaw, the alveolar 

 margins are strongly flared below the carnassial and the last 

 two premolars. The extent of this spreading possibly exceeded 

 that in the hyaenas. 



Dentition . — The dentition contains a most remarkable mixture 

 of primitive characters with some extreme specializations. 

 The formula 3, t, », s, shows the loss of but a single 

 tooth, Pt, while the efficient portion of the dentition may 

 be said to consist of but three teeth, a fairly developed canine, 

 a powerful Pt and a still heavier Mr. 



The incisors are missing from both rami but the clearly 

 defined alveoli show that they were small and crowded. It 

 and It were near the size of the corresponding teeth in the 

 hyaena but Br was much more reduced. 



The lower canines are short and stout and appear a little 

 weaker than in the hyaenas. 



Of the three premolars, Pt has been lost but its alveolus 

 shows it to have been a thick, single-rooted tooth somewhat 



