ABSTRACTS OF PAPERS 133 



have been assembled with a considerable degree of certainty as to the associa- 

 tion : first, through the extremely careful records which were kept of the loca- 

 tion of every bone in the quarry ; second, through their propinquity ; third, the 

 careful fitting and articulation of the bones ; finally, through careful compara- 

 tive measurement of size. It now appears certain that few of the bones had 

 drifted a long distance ; they were mostly deposited not far from the carcasses 

 to which they had belonged. 



The last twelve months of laboratory work in the American Museum of Nat- 

 ural History has resulted in bringing together several skeletons which are 

 practically complete, and certainly in more than one case belonging to one 

 individual, together with a number of skeletons in which the association of 

 the bones is probably but not certainly correct. 



From this wonderful material it has been possible to supplement the full 

 descriptions of this animal which were published in 1909 by Messrs. Holland 

 and Peterson, and to give for the first time the absolute form and proportions, 

 the pose, and the articulations of the fully adult Moropus, of very large size. 

 This and other materials will soon be described by the present author. 



In the meantime Moropus may be characterized as a forest-loving, slow- 

 moving animal, not improbably frequenting rather swampy ground. The small 

 head, relatively long neck, high fore quarters, short, downwardly sloping back, 

 straight and elongated limbs, suggest a profile contour only paralleled by the 

 forest-loving okapi among existing mammals. The foot structure, of course, 

 is radically different from that of the okapi, but we should not regard it as 

 fossorial, or of the digging type, because it is not correlated with a fossorial 

 type of fore limb. It would appear that these great fore claws, in which the 

 phalanges were sharply flexed, were used in pulling down the branches of 

 trees and also as powerful weapons of defense. 



A LONG-JAWED MASTODON SKELETON FROM SOUTH DAKOTA AND 

 PHYLOGENY OF THE PROBOSCIDEA 



BY HEjSTRY FAIRFIELD OSBORN 



(Abstract) 



Cope's family classifications were morphological and horizontal rather than 

 phylogenetic and geological. Finding one or more single characters possessed 

 in common at certain horizontal periods of geologic time by mammals in differ- 

 ent lines of evolutionary descent, h^ seized on these common characters as 

 convenient keys to classification. First ^ for the order Perissodactyla and then 

 for the families of rhinoceroses ^ and titanotheres ^ I have reached the opinion 

 that Cope's method of morphological classification is untenable, that the only 

 true and permanent claiLjdification is phylogenetic. Other paleontologists, how- 

 ever, have reached a different opinion. 



1 Fossil mammals of the Wasatch and Wind River beds. Collection of 1891. (With 

 J. L. Wortman.) Bull. Am. Mus. Nat. Hist, vol. iv. art. xi, Oct. 20. 1892, pp. 81-147. 



- Phylogeny of the rhinoceroses of Europe. Rhinoceros contributions No. 5. Bull. 

 Am. Mus. Nat. Hist., vol. xiii, art. xix, Dec. 11, 1900, pp. 229-267. 



3 The four phyla of Oligocene titanotheres. Bull. Am. Mus, Nat. Hist., vol. xvi. art. 

 viii, Feb. 18, 1902, pp. 91-109. 



