342 



University of California Publications in Geology 



[Vol. 12 



Dinarctotlierium merriami Barbour'^^ from a giant liumenxs in the 

 Nebraska University collections. 



In the following pages the author describes a fourth American 

 Pliocene bear from two upper earnassials and a first upper molar, 

 collected in the Eden by his assistant, Mr. Rak. This is the first 

 discovery of an ursid in American deposits of early Pliocene age. 

 The earnassials associated with tliis specimen make possible a definite 

 comparison witli the splendid Rattlesnake material. 



HYAENAECTOS GREGOEYI, n. sp. 



Type. — A worn upper carnassial tootli from the left side of the jaw, Univ. 

 Calif. Coll. Vert. Pal. no. 24025 (figs. 49o, 49b), Univ. Calif, loe. 3269. 



Referred material. — The material referred to this species consists of an upper 

 first molar from the left side, Univ. Calif. Coll. Vert. Pal. no. 24026 (figs. 51o- 

 51('), and a somewhat smaller upper carnassial from the left side, Univ. Calif. 

 Coll. Vert. Pal. no. 24027 (figs. 50o, 50b) ; both from the same general locality 

 as the type specimen. 



Characters. — The unusually large size of the protostyle, the direct 

 anterior position of the same in relation to the protocone ; the anterior 

 extension and the anteroposterior length of the deuterocone ; the lack 

 of a marked external eingulum in the referred the central position 

 of the inner ridge of this tooth in relation to the imaginary line of the 

 main cusps and that of the interior tooth margin, and the marked 

 diagonal direction of the same inner ridge. 



Description. — The anteroposterior diameter of the type carnassial 

 (no. 24025, figs. 49a-49?)) is 1.33 times the greatest transverse diameter. 

 The tooth evidently belongs to an old individual, the lobes having been 

 considerably worn away. A single, deeply worn, indented surface now 

 joins the two main posterior cusps (tritocone and protocone) to the 

 third but slightly smaller cusp, lying directly anterior to the two first 

 (the protostyle, or "talon" of Dr. Lydekker), and to the elongate cusp 

 which is appressed against the inner margin of the first two (the 

 deuterocone). At the anterior extremity of the tooth the edge of 

 the downward-sloping triturating surface cuts the top of the root. 

 A eingulum follows the external contour, which, generally convex, 

 becomes slightly concave opposite the anterior and posterior extremi- 

 ties of the protocone. A heavier eingulum crosses the inner margin 

 of the deuterocone. A constricted, anteriorly directed valley separates 



32 Barbour, E. H. Neb. Geol. Surv., vol. 4, pp. 349-353, 1916. 



