from Aorth- western Patat/ouia. 201 



lUEN'OMYS*, gen. nov. 



General fnclca as iti Oryzomtjs. Unpor inci.sora grooved. 

 Moliira l»y|)8oduiit, laminate, the lamiiu'O lozenge-shaped in 

 section. 



Genotvp>«, /. Ivuqicaudiitus [Reiihrodon fonoicandatus, 

 Pl.il.t).' / 



The skull, judging by an ininialure example, la on the 

 whole not unlike that of P/ii/llotis, and presents no very 

 special peculiarities. The interparietal is of fnll size. The 

 zygomatic |)lafe is of average breadth, but little projected 

 forward, not undercut. Palatine foramina li)ng, penetrating 

 between the molars. The internal pterygoids, however, are 

 unusually thickened, flattened, and turned outwards above, 

 though this nuty be partly due to immaturity. Bulla3 of 

 medium size. 



Upper incisors with a sharply defined groove. 



Midars veiy peculiar, hypsodont, laminate, with three 

 laujiiite to m\ two to m' and nj\ and the same numbers in 

 the three molars below. The laminaj of the upper teeth are 

 very much as if the re-entrant angles of each side in the teeth 

 of Phyllutis penetrated further into the teeth, so as to cut 

 connection between the dentine spaces of each lamina, while 

 still leaving the laminje lozenge-shaped and just touching 

 each other at these median points. As a result, the shape in 

 section of the lamiiire in a young animal is almost precisely 

 similar to that in the African elephant, as viewed vertically, 

 though of course the spaces between the lamina are not tilled 

 up with cement. Such teeth as these would in old age wear 

 down to a sufficient approximation to Philippi's figure to 

 render it certain that the two animals are congeneric. 



This new genn.s is undoul>tedly quite distinct from any 

 previously recognized, and it is not easy to be certain as to 

 its relationship to others. Piobably it is most nearly allied 

 to Phyllutis^ of which it may be looked upon as a relative 

 with grooved incisors and simplified molars. But, in any 

 case, the difference is very considerable, and the study of 

 adult specimens may cause some modification of this opinion. 



Sr. Budin noticed that the single specimen was dist net 

 from the ordinary Oryzomys, to which it has so marked a 

 re.<euiblance, and did all in his power to get further examples, 

 but without success. 



"Caught among the roots of fallen trees, like all the other 

 species of the Beatriz peninsula." — K. li. 



• So nnuied as a memento that its recognition coincided with the 

 arrival of a glorious peace, 

 t An. Mub. Nut. Chile, pt. 11. " Muridse of Chile," p. 04 (1900). 



