1880. | On the Extinct Cats of America. 845 
cally different from the others enumerated in this chapter. It is 
inferior in size, and peculiar in the reduced symphyseal and in- 
Fig. 7.—Nimravus gomphodus, two-fifths natural size. Mus. Cope. From Vol. 
Iv, U. S. Geol. Surv. Ters. 
cisive parts of the mandible. It was found by Mr. Wortman in 
the bad-lands of the John Day valley, Oregon. 
Division TII. The Primitive Sabre-tooths. 
Dinictis Leidy. 
With this genus we enter the group of the primitive sabre- 
tooths, commencing with the most generalized form. The skele- 
ton is yet unknown, but the skull and dentition are those of a 
true sabre-tooth, and there seems to be no ground for believing 
the Musteline affinities suggested by Leidy! It occupies the 
lowest position on the line of the sabre-tooths, on account of its 
humerous and simply constructed molar teeth, and stands in im- 
mediate connection with the false sabre-tooth group, having ex- 
actly the dental formula of Alurogale Filh. On this account I 
formerly united the two genera, but now believe that the absence 
of the inferior flange of the mandible in 4Z/urogale is sufficient 
ground for maintaining them as distinct. The latter genus, in 
this respect, exactly resembles Archelurus and Nimravus. 
Remains of this genus are quite abundant in the White River 
roi Extinct Mammalia, Dak., Nebr., p- 64- 
