100 BULLETIN OF THE 



coloration. Professor Baird provisionally refers them to the Ursus ameri- 

 canus, var. cinnamomeus, ol' Audubon and Bachman, to which, he says, 

 they bear the nearest resemblance. 



Prince Maximilian, in his memoir "Uber die Selbst'andigkeit der species 

 des Ursus ft rox Desm.," * urges strongly the distinctness of I '■ horribilis {fcrox 

 Maxm.) from both U. americanus and U. arctos, in which he is supported 

 by the anatomical observations of Dr. C. Mayer, which form an appendix 

 to his paper. Several specimens of the former, of different ages, from the 

 Upper Missouri, are described in detail, but no differences other than those 

 previously pointed out by other authors, arc mentioned. They consider 

 thnt the shorter ears and longer claws of U. horribilis, with certain minor 

 osteological peculiarities, sufficiently distinguish it from U. arctos. These 

 authors admit that bears from northern countries present great individual 

 differences; yet, in reviewing Middendorff's arguments, they offset their 

 conclusions, based on an examination of a very limited number of speci- 

 mens, against those of the latter, formed from probably as careful an elabo- 

 ration of many times their amount of material. The differences that have 

 been described by authors as occurring between specimens of U. arctos 

 from different parts of Europe and Asiatic Russia, or between different 

 specimens of either U. horribilis or U- americanus from different localities 

 on this continent, are as great as those they urge as peculiar to their 

 so-called species. 



I have not space to notice in detail each point urged as distinctive by 

 those authors who divide the bears into a large number of species. As they 

 mainly rest on the shape and size of the molar teeth, the relative length of 

 the claws and the ears, and the proportions of the skull, a few further 

 remarks on these characters may not be out of place. In Professor Baird's 

 table of measurements of skulls of American bears, the average proportion 

 of breadth to length in the seven specimens cited is sixty per cent, with a 

 minimum of fifty-five per cent, and a maximum of seventy-one. Only one 

 of the series, however, exceeds sixty. Adding four other specimens referred 

 by Baird to " cinnamomeus f " the average of the eleven is fifty-nine and a 

 half per cent ; the minimum is fifty-three, and two specimens range above 

 sixty. The proportional breadth of the skull in eight specimens of U. hor- 

 ribilis is fifty-six per cent. Between the extremes of this scries (Nos. 1218 

 and 2037) the variation amounts to ten per cent. In his comparison of U. 

 horribilis with U. arctos, Baird cites two of Blainville's specimens in which 

 the same proportion is sixty-six per cent; in reference to which he adds: 

 '• This width of head far exceeding that of any well-known American 

 species, would appear to be quite conclusive as to identity," — Professor 



* Verhandlungen der Kaiserliclien Leopoldinisch-Carolinischen Akademie der Natur- 

 forschung, Band. XXVI, erste Abtheil., 1857, pp. 33 - So, Taf. Ill, IV, and V. 



