684 REroKT— 1897, 



FRIDAY, AUGUST 20. 

 The folloA\aug Papers and Reports were read : — 



1. Reconstruction and Model o/ Plienaoodus primtevus, Coi^e. 

 By Professor Henry Fairfield Osborn. 



The famous skeleton of Phenacodus, belonging to the Cope Collection, which 

 came into the possession of the American Museum of Natural History in 1895, has 

 been entirely freed from the matrix and remounted in such a manner that every 

 part can be removed for study. This remounting gives quite a different conception 

 of the animal from that presented in the original mounting, as illustrated before 

 the Section in an enlarged photograph of the fossil skeleton and a wax model 

 by Charles Knight. Phenacodus is digitigrade as the tapir. Its proportions are 

 very peculiar and widely different from those of any modern ungulate, consisting 

 of an extremely small head, short neck, short fore-limbs, long hind-limbs, 

 powerful hind-quarters and tail, and upwardly arched back. Phenacodus is not 

 ancestral to any of the modern Ungulata because its ancestor Euprotogonia is 

 similarly specialised, although found in the basal Eocene. These animals, how- 

 ■ever, give us a picture of the true ancestral ungulate type and forcibly demon- 

 strate the derivation of the hoofed from the clawed animals. The model of 

 Phenacodus shows its many points of likeness to the general build of the Creodonta 

 or ancient Carnivora. 



2. On Skeletons and Restorations of Tertiary Mammalia. 

 By Professor Henry Fairfield Osborn. 



This paper, illustrated by numerous photographs of the mounted skeletons and 

 of Charles Knight's restorations, set forth the special methods instituted by the 

 author in the American Museum of Natural History. The field work which 

 began six years ago is planned as a complete /«Mwa/ survey oi the ancient Tertiary 

 lakes, the Eocene and Oligocene being now nearly complete, and future work 

 extending into the Miocene and Pliocene and back into the Mesozoic. Careful 

 records of horizontal distribution of species are preserved and numerous new 

 faunal subdivisions have already been clearly defined. Two other features of the 

 field work are the extremely skilful and thorough methods of collection and the 

 efforts made to secure complete skeletons suitable for mounting, the ultimate object 

 being to secure and exhibit every stage in the development of the more important 

 types. Ten complete skeletons have already been mounted as follows : Protoro- 

 hippus, Hyrachyus, Palceosyops, Titanotherium, Phenacodus, Coryphodon, Acera- 

 iherium, Metamynodon, representing the ungulates ; Patriofelis and Hoplophoneus, 

 representing the unguicidates. The special features of the museum work are the 

 immediate cataloguing of the collections, which now include upwards of 10,000 

 individuals, and their division into a study and exhibition series, both of which are 

 readily accessible to investigators. The mounting of the skeletons vastly increases 

 their interest to the general public. Each skeleton, as exhibited, will be accom- 

 panied by a model representing its former muscular proportions and by a large 

 coloured restoration giving an idea of its appearance when alive, its habits and 

 environment. A double set of labels will also be adopted, separating the popular 

 from the purely scientific information. The methods of field collection are 

 popularised by means of large coloured transparent photographs hung in the 

 windows, taken in the field especially for this purpose. 



