138 Fossil Bones from Oregon Territory. 



of this tooth you will perceive four facets looking towards each 

 other, with an intervening, transverse, polished furrow ; and it is 

 to this part to which I would especially invite attention, and a 

 careful comparison with the generic characters of Megatherium 

 as given by Fischer,* which I quote : " Dent prim et Ian \ ; 

 molares j^, obducti, tritoris, coronide nunc plana transversim 

 sulcata, nunc medio excavata marginalis prominalis." The lower 

 part of the tooth is of the same shape and size as the crown, with 

 a conical cavity at its base. It is a tooth of the Mylodon (Owen), 

 Megalonyx (Harlan)? 



The larger fragments above alluded to are two in number, 

 which from their striking resemblance to the extremities of the 

 humerus, I cannot but consider as portions of that bone. (See 

 Fig. 2.) A, head of the bone ; B, the greater, C the smaller tu- 

 berosity. The length of the largest fragment (from A to D) is 

 fourteen inches ; its breadth measured across the tuberosities, 

 seven and a half inches ] the diameter of the head of the hume- 

 rus, four and a half mches ; the circumference of the body of the 

 bone just below the tuberosities, fourteen and a half inches; from 

 the summit of the external tuberosity to the prominence E (see 

 Fig. 4) on the front of the bone, twelve inches. There are the 

 remains of a large protuberance on the outside of the humerus, 

 a htile more than half way down the body of the bone, which 

 bears a strong resemblance (if my memory does not fail me) to 

 a marked projection on the humerus of the Orycteropus. Some 

 small portions of the front and back of the body of the bone are 

 wanting ; but the lowest parts on the sides correspond with the 

 fractured surface of the lower extremity, which I will now de- 

 scribe. 



On this portion are to be seen the external (F) and internal 

 (G) condyles, and the articulating surface of the elbow joint (H); 

 and on the back part. Fig. 3, a large deep hollow, I, for the re- 

 ception of the olecranon process of the ulna; the internal larger 

 half of the articulating surface (Fig. 2, a) presents the appear- 

 ance of a hinge joint, and seems well adapted for progression, 

 while the outer half presents a large smooth, round ball, (Fig. 2, 

 6,) upon which the head of a radius might freely roll. The 

 breadth of this fragment measures across the condyles, eleven 



* Penny Cyclopedia, under Art. Megatherium. 



