LIMNOHYUS. 705 



rior molar teeth from the present species. That animal appears to lack the 

 intermediate tubercles and crest, and has a much stronger external cingulum. 

 The P. horealis has been only found thus far in the Wind River Eocene 

 by Mr. J. L. Wortman. 



LIMNOHYUS Leidy. 



Proceedings Academy Natural Sciences, Philadelphia, 1872, p. 242 ; Cope. Annual Report U. S. Geol. 

 Survey Terrs., 1872 (1873), p. 593. Palceosyops, Marsh, Amer Joum. Sci. Arts, 1872, p. 122, not 

 of Leidy, 1871. 



This genus only differs from the last in possessing two conic tubercles 

 of the inner series on the last superior molar, instead of one, a character 

 first pointed out by Marsh. 



It is yet uncertain to what genus the species originally described by 

 Leidy as Palceosyops paludosus belongs. The type specimens do not include 

 the last superior molar, according to Leidy. The only superior true molar 

 preserved possesses two internal cusps, and is, according to its describer, 

 the second of the series. Professor Marsh, in arranging the species of the 

 two genera, came to the conclusion that the last superior molar of the P. 

 paludosus possessed two internal cones, which character he adopted as 

 distinctive of the genus Pakeosyops. To the species with one inner lobe, 

 he gave the name of Lininohyus. Subsequent to the original description of 

 the P. paludasus, Leidy referred to it various specimens with only one 

 internal cone of the last superior molar, and at that time defined the genus 

 Paloeosyops as distinguished by that character. Thus Professors Marsh and 

 Leidy were at issue as to which of the genera should receive the name 

 Palceosyops. 



The decision of the question will depend on the rule adopted as to the 

 conditions necessary to be observed in the proposal of new generic names. 

 Those authors who deem it sufficient to establish a generic name, that it be 

 merely printed, will follow the course adopted by Professor Marsh. In 

 describing the original P(dceosyops paludosus Dr. Leidy did not characterize 

 the genus Paloeosyops. This is a custom more to be honored in the breach 

 than the observance, and one contrary to the rules of nomenclature. For 

 the present writer the name Palceosyops did not at that time obtain a posi- 

 tion in nomenclature. This was fully acquired at a later date, when Dr. 

 45 o 



