Eaton — Vertebrate Fossils from Ayusbamba, Peru. 145 



brachyceros as defined by Professor Lydekker,* who states : " It 

 does not appear that this deer comes close to any existing 

 species." 



Philippi has caused some confusion by giving the name 

 Cervus brachyceros to three individuals of the Venado de 

 Cajamarca, which he proposed to separate, under this name, 

 from the recent species of Andean deer, Odocoileus antisiensis 

 = Cervus antisiensis.^ It is apparently far from Philippi's 

 intention to convey the idea that the Pleistocene Odocoileus 

 brachyceros has persisted until the present time. The antlers 

 of this fossil species are quite different from those of the recent 

 deer to which a similar specific name has been thus 

 unfortunately assigned. 



Dibelodon bolivianus. 



Remains of Dibelodon were the most abundant fossils at 

 Ayusbamba, bones and teeth, usually dissociated and incom- 

 plete, occurring at various places in the beds of clay and 

 gravel, and also superficially. It is significant of the history 

 of these deposits that only small and compact bones should 

 have been preserved entire. The individuals of the species, 

 whose remains were found here, differed considerably in size, 

 and it appears from the dentition and from the condition of 

 the epiphyses that many of these animals had not attained 

 their full growth. An accurate comparison of their mature 

 size with that of other mastodons cannot therefore be made. 

 The maximum stature indicated by the largest bones is not 

 more than three-quarters as great as that of the medium-sized 

 example of Mammut americanum, whose mounted skeleton is 

 exhibited in the Peabody Museum' of Yale University. The 

 height of this animal, taken at the shoulder, is about 8 feet and 

 3 inches. 



Of the six South American species of Mastodon described 

 by Ameghino,^: the two most generally recognized are 

 M. andium, Cuv., and M. humboldti, Cuv. According to Pom- 

 peckj§ there are two other valid species, namely, 31. bolivi- 

 anus, Philippi (emend. Pompeckj), and M. chilensis, Philippi. 

 While Pompeckj does not adopt Cope's separation of Dibelodon 

 and Tetrabelodoii from Mastodon, it should be understood 

 that both M. bolivianus and M. chilensis, as well as M. andium 

 and M. humboldti, belong to the Dibelodont division of the 

 original genus. 



* Paleontologia Argentina, II, p. 79. 



f Anales del Museo Nacional de Chili, 1894, Entr. 7, Priraera Seccion, p. 5. 

 % Mamif eros Fosiles de la Eepublica Argentina. 



$3 Mastodon -Eeste aus dem inter-andinen Hochland von Bolivia. Palason- 

 tographica, vol. lii, 1905. 



