merriam ] Pliocene and Quaternary Canidae. 283 



we have some acquaintance with the limb structure. Some of 

 the characters suggest a distant relationship to the Amphicyo- 

 nines, though this is indistinct and a very wide, gap must be 

 filled before we can prove that the actual ancestors are to be 

 found in that group. We can feel assured that in whatever 

 division it is finally shown to belong, its place will be near the 

 outer border of the group. 



Measurements. 

 Length of mandible from anterior end of symphysis to 



posterior end of Mi 112 mm. 



Height of jaw below protoconid of Mi 38 



Greatest thickness of ramus below protoconid of Mi. .. 20 



Length of premolar series 41 



" " molar series 48 



Greatest diameter of base of canine 1(3 



Antero-posterior diameter of P3 10 



» ii ii ii p T 22 



» » >> Mr 30.5 



» » " Mi 10 



Transverse diameter of Ps 8.5 



" » " V, 17 



» » » Mx 16 



» » " M3 8.5 



HYAENOGNATHUS ? (PORTHOCYON U. gen.*?) DUBIUS U. Sp. 

 Pl. 29 and Pl. 30, Fig. 1. 



Distinctive characters. — Muzzle short, forehead and sagittal 

 crest high. Brain case small and narrow, outer -walls sloping 

 sharply from the crest. Wings of the premaxillaries reaching 

 back to the blunt anterior ends of the frontals. Palate very 

 broad, with two pairs of large posterior palatine foramina. 

 Posterior nasal openings not reaching forward to the end of the 

 molar series. Dentition -', -, -. I- very large. Premolars 

 crowded. Sectorial massive, without deuterocone. Metacone 

 and heel of M 1 small. M- reduced. 



Occurrence. — This form is represented by a single specimen 

 consisting of the greater portion of a cranium with the essential 

 parts of the dentition (No. M8138, Univ. Calif. Palaeont. 

 Mus.). It was found in a quarry about two miles southeast of 



