XVII. DIPTERUS REMAINS FROM THE UPPER 

 DEVONIAN OF COLORADO.* 



By C. R. Eastman. 



The first announcement that strata of Devonian age occur in the 

 San Juan region of Colorado was made by F. B. Meek^ more than 

 three decades ago, after an examination of some invertebrate fossils 

 collected by F. M. Endlich of the Hayden Survey during the summer 

 of 1874. A few fish remains were also obtained from the same beds 

 by Endlich, who remarks upon their occurrence as follows: "Besides 

 these, scales and fragments of bones are found, belonging to some 

 fish of considerable size. Too little material could be collected to 

 admit of any identification, even only generically. Small scutella^ 

 also occur, probably belonging to the same animal. "^ 



During the more recent survey of the San Juan country under the 

 direction of Dr. Whitman Cross large collections were made from the 

 two formations which have been found to carry Devonian fossils in 

 southwestern Colorado, and the extensive faunas that have been 

 brought to light from the Upper Devonian and Lower Carboniferous 

 of this State are now satisfactorily known, thanks more especially to 

 the studies of G. H. Girty.^ 



The limestone formation from which Devonian fossils were first 

 obtained by Endlich is known as the Ouray limestone, this term 

 having been proposed by A. C, Spencer* in 1900. It yields over 

 thirty species of invertebrates and one species of fish, the latter 

 described by O. P. Hay^ under the name of Cladodus formosus. In 

 the words of Dr. Whitman Cross,^ "the position of the Ouray lime- 



* Published by the permission of the Director of the U. S. Geological Survey. 



> Bull. U. S. Geol. and Geog. Survey, 2d Ser., no. i, 1875, p. 46. 



2 Ann. Rep. U. S. Geol. and Geog. Survey for 1874. pp. 211-214. 



3 Devonian Fossils from Colorado. The Fauna of the Ouray Limestones 

 U. S. Geol. Survey, 20th Ann. Rep., pt. II, 1900, pp. 25-81. — The Carboniferous 

 Formations and Faunas of Colorado. Professional Paper No. 16, U. S. Geol. 

 Survey, 1903. 



< "Devonian Strata in Colorado," Amer. Jour. Sci. [4], Vol. IX, 1900, p. 125. 

 6 " Description of a New Species of Cladodus, etc.," Amer. Geol., Vol. XXX, 



1903, pp. 373-4- It is suggested in his paper that the age of the Ouray limestone 

 may be late Middle or early Upper Devonian. 



6 "A New Devonian Formation in Colorado," Amer. Jour. Sci. [4]. Vol. XVIII, 



1904, p. 246. 



279 



Mas* ^/ 



