232 PROCEEDINGS OF THE NATIONAL MUSEUM vol.83 



with one more tooth absent, probably P2. P4 of about the same length 

 relative to Mi as in Palaechihon, but relatively higher, with no trace 

 of the metaconid and only a very vague rudiment of the paraconid. 

 Mi-2 similar to Palaechthon, but M3 with smaller third lobe and un- 

 divided hypoconulid. Upper molars comparable with Paromomys and 

 Palaechthon but very slender, transverse, and more triangular, 

 posterointernal expansion much weaker, inner base not bilobed, and 

 M^ shorter relative to M^. 



Order CARNIVORA 

 Family ARCTOCYONIDAE 



Gidley (1919, op. cit.) placed most of the Fort Union and some of 

 the Torrejon arctocyonines in a new genus, Neoclaenodon. Thorough 

 restudy with greatly augmented materials shows that the separation 

 from Claenodon is not valid. It was based essentially on one specimen 

 of each supposed genus, and analysis of many specimens shows that 

 a generic distinction docs not exist. Among many other points this is 

 emphasized by the fact that Gidlej^ defines Neoclaenodon as having the 

 premolars more reduced than in Claenodon, and Matthew (ms.) says 

 they are less reduced in Neoclaenodon. 



There is a new species of this group, collected since Dr. Gidley's 

 death, and a new genus based on a new species recognized but not 

 published by him. 



Genus CLAENODON Scott 



CLAENODON VECORDENSIS." new species 



r^/pe.— U.S.N.M. no. 13781, left M^-^. Collected by A. C. 

 Silberling and G. G. Simpson, 1932. 



Horizon and locality .—LoQuMij 9, 300 feet above base of the 

 recognized Fort Union, Crazy Mountain Field, Mont. (This is about 

 900 feet below the Gidley Quarry, but probably still in the Middle 

 Paleocene.) 



Diagnosis. — M^ similar to that of C. silherlingi in outline but 10 to 

 20 percent larger, somewhat more transverse, hypocone vestigial, and 

 strong, crenulated internal cingulum. M^ relatively as large as in C. 

 jerox and similar, but metacone smaller, external border more evenly 

 rounded, and hypocone ])rescnt although rudimentary. M^ length 

 9 mm, width 13.5 mm. M^ length 6.7 mm, width 10 mm. 



DEUTEROGONODON,28 new genus 



Type. — Deuterogonodon montanus Gidley, new species. 

 Distribution. — Middle Paleocene, Fort Union, Mont. 



*» Vecors, cr&zy-\—ensJs, geographical adjectival suffix. 



w A«uT«poi, second, subsequent +7wWa, angle +6Sovs, tooth. Named in analogy with Protogonodon. 



