THE AMEBIC AN BISONS. 29 



3. Fragment from California (Whitney's Coll.), 18 mm. long, — portion extending from the inner angle 



to the front edge of first molar. 



4. Fragment from California. (National Museum Coll.) 



5. Georgia specimen. (Measurements in part from Harlan, and in part from Owen's figure.) 



In the National Museum at Washington there is still another fragment of 

 a lower jaw (No. 8270 of the National Museum Register), consisting of a 

 large part of one ramus, from Alameda County, California, presented by Dr. 

 L. Gr. Yates.* This specimen is of about the size of the larger of the two 

 California specimens already described. 



Dr. Harlan's measurements of the Georgia specimen, determined by aid 

 of Prof. Owen's figure,! are also added to the table. As already stated, it 

 indicates a species as large as Bison antiquus, the jaw being heavier and 

 thicker even than in the largest known specimen of that species. The 

 length of the molar series seems, however, a little less, but this measure- 

 ment can be only approximately determined. 



Of the metacarpal bones of Bison antiquus but a single specimen is 

 known. This was collected by Mr. J. Lockhart, and is contained in the 

 National Museum at Washington. It is about one tenth longer than the 

 largest metacarpal of Bison americanus I have been able to find, and is rela- 

 tively much stouter. It is also rather longer and stouter than the corre- 

 sponding part in a very large old male Bison bonasus. It hence about 

 equals the size of this part in Bison prisons. In Table VII will be found 

 measurements of this bone as compared with those of the corresponding 

 part in Bison americanus (male and female), Bison bonasus (male), and of a 

 large domestic bull. 



Having at hand a large series of metacarpal bones of Bison americanus, I 

 add here a table of measurements showing the range of variation in this 

 part, resulting from age, sex, and individual differentiation, found in a 

 series of nearly a hundred specimens. This series shows that some of the 

 specimens belonging to females are as long as the average of the males, and 



* Since the foregoing was put in type 1 have received a letter from Dr. Yates, dated " Centreville, Ala- 

 meda Co., Cat, Jan. 29, 1876," announcing the recent discovery by him of another skull of the fossil bison in 

 California. He says: "I found a splendid specimen last week which I shall preserve. It consists of the 

 skull, with three molar teeth on one side, and the greater portion of the horn-cores. It was so soft that I 

 had to bed it in plaster before I could take it out." He adds that " the skull was found in post-pliocene 

 gravel, about ten feet from the spot where I found the skidl of a fossil elephant some ten years ago, and in 

 the same deposit where I have found Mastodon, Eouus, Auchenia, etc." 



f Journ. Acad Nat. Sci. Phila., 2d Ser., Vol. I, pi. vi. 



