PROCEEDIXGS: BIOLOGICAL SOCIETY 333 



stone mapped as Fox Hills at Horse Creek should prove to be ]\lesa- 

 verde, this would not have any necessary bearing on the correlation of 

 the Fox Hills sandstone of northern Colorado. The area from Fort 

 Collins and Greeley south to Boulder has recenth' been examined with 

 care, and full collections of fossils have been obtained from the Fox 

 HiUs. The Fox Hills fauna of this area corresponds closelj' '^Ndth the 

 typical Fox Hills fauna of northern South Dakota, and the identifica- 

 tion of the same formation in the two areas is as complete as can be 

 expected over such a great distance. While it is true that the Fox 

 Hills fauna may be considered the littoral facies of the Pierre fauna, 

 and that in a broad sense it began long before Fox Hills time in the 

 Eagle and was repeated in the Claggett, yet each of these recurrences 

 has its distinctive species, so that when the fauna of the whole forma- 

 tion is considered it is not difficult to distinguish Fox Hills from Claggett 

 and Eagle, though they have a good many species in common. 



The true Fox Hills fauna of the type area is distinguished from all 

 the earlier faunas of the region by the presence of the ammonite *Sp/?e/z- 

 odiscus instead of Placentoceras, bj' a group of Scaphites including .'^. 

 conradi, S. nicolleti, S. cheyenneiisis, S. mandanensis, by a number of 

 gastropod genera and species, and by the absence of Baculites, Inoce- 

 ramus, etc. In all these respects the Fox Hills fauna of northern Colo- 

 rado is identical. Heroy's proposed correlation of the Fox Hills of 

 northern Colorado with the ]\Iesaverde of northern Wyoming cannot 

 be accepted because the detailed paleontologic evidence is opposed to 

 it, and because there are several important lower sandstones within 

 the Pierre shale of northern Colorado which probably represent Mesa- 

 verde sedimentation. Time was lacking for an adequate discussion of 

 the papers by Hares and Ashley. Concerning the latter, Stanton re- 

 marked that many of the opinions expressed could be characterized as 

 "interesting if true." 



C. X. Fenner, Secretary. 



THE BIOLOGICAL SOCIETY OF WASHIXGTOX 



The 537th meeting of the Society was held at the Cosmos Club, 

 Saturday, ^larch 6. 1915, at 8 p.m., with Ex-President Stejneger 

 in the chair and 60 persons present. 



Under the heading Brief Xotes A. S. Hitchcock called attention to 

 the plans and methods of work in preparing a new Flora of the Dis- 

 trict of Columbia, which it is hoped, will be completed within a year. 

 It will contain analytical keys to the genera and species of ferns and 

 flowering plants found within a radius of 15 miles of the citj^ of Wash- 

 ington, but will not include descriptions. 



The first paper of the regular program was by J. W. Gidley: Xotes 

 on the possible origin of the bears. After the examination of much fossil 

 and living material the speaker had arrived at the conclusion that 

 the bears, constituting a small homogeneous, widely distributed group. 



