NATURAL SCIENCES OP PHILADELPHIA. 359 



August 3. 

 The President, Dr. Ruschenberger, in the chair. 

 Seventeen members present. 



The following papers were presented for publication : 



" On the Batrachia and Reptilia obtained during the Exploration 

 of Talamanca, Costa Rica, by Wm. M. Gabb." By Edw. D. Cope. 



"On the Reptilia obtained by Dr. John M. Bransford, U.S.K, 

 during the survey of Nicaragua of 1874." By Edw. D. Cope. 



"Studies of the American Falconidse." By Robt. Ridgwaj'. 

 "No. III. Monograph of the genus Micrastur." 



"On the Food and Nidification of certain North American 

 Birds." By Thomas G. Gentry. 



"On the occurrence of Uranium, Silver, Iron, etc., in the Ter- 

 tiary Formation of Colorado Territory." By E. L. Berthoud. 



On (he Cretaceous Beds of the Galisteo. Prof. Cope laid on the 

 table a stitched copy of his memoir on the vertebrate fauna of the 

 cretaceous period in the west, being Vol. II. of the 4to. series of 

 Haj'den's Reports of the U. S. Geological Survey of the Territories. 



Prof. Cope made some remarks on a paper recently published 

 by the American Philosophical Society, entitled the Geological 

 Relations of the Lignitic Groups of the Cretaceous, by Prof. John 

 J. Stevenson. While he regarded the paper as a valuable contri- 

 bution to the literature of the subject, he thought that some asser- 

 tions of the author required notice. Thus his remark that verte- 

 brate life is too imperfectly preserved to be ordinarily of much 

 service alone [in fixing geological horizons] could not be con- 

 curred in by students of the extinct vertebrata. A similar state- 

 ment respecting fossil remains of plant-life is the following: " Such 

 is the record of plant-life a record little better than a blank, with 

 here and there a few markings, many of which are too indistinct 

 to be deciphered." This view would naturally not be acceptable 

 to students of fossil plants, nor could it in the nature of things 

 be true. Plants offer too many tangible structural features to be 

 worthless as evidence, and the only remark which can be justly 

 made in criticism of the paleophytologists is that they have not 

 always correlated their results with those of the paleontologists. 

 The failure to insist on the tertiary character of the vegetation 

 of the Fort Union beds of the West, would have rendered less 

 prominent the most important generalization yet derived from the 

 study of that horizon, viz., that a cretaceous fauna was contem- 

 porary with a tertiary flora. 



