218 PROCEEDINGS OF THE ACADEMY OF 



September 3. 

 Dr. Bridges in the chair. 

 Seventeen members present. 

 The following papers were presented for publication : 



" Catalogue and Synonymy of the Family Laseidse." By Geo. 

 W. Tryon, Jr. 



" Catalogue and Synonymy of the Family Galeommidse." By 

 Geo. W. Tryon, Jr. 



" Catalogue and Synonymy of the Family Leptonidse." By 



Geo. W. Tryon, Jr. 







Remarks on the Habits of an AnLPvot Leidy remarked that 

 in his recent visit to Fort^Bridger, Wyoming, in many places he 

 observed the nests or hills of an ant, which reminded him of a 

 communication formerly made to the Academy by Mr. Lincecum. 

 on the Agricultural Ant of Texas (1866, 323). The ant-hills con- 

 sisted of "conical piles of gravel from one to two feet in diameter 

 and from six inches to a foot in height, occupying the centre of a 

 bare, circular level several yards in diameter. The mode of for- 

 mation and object of the circular space were not ascertained. 

 Probably it was the accidental result of the insect feeding on all 

 kinds of vegetation growing within a circumscribed limit. Mr. 

 Lincecum described similar circles, or pavements as he calls them, 

 and stated that the ants allow nothing to grow upon them except- 

 ing a certain grass, Aristida stricta, from which they collect the 

 seeds when ripe. 



September 10. 

 The President, Dr. Kuschenberger, in the chair. 

 Twenty-three members present. 



The following paper was presented for publication : 

 " On the Agency of Insects in obstructing Evolution." By 

 Tuos. Meehan. 



Remarks on Mineral Springs, &c, of Wyoming and Utah. 

 Prof. Leidy observed that, in his recent trip to Wyoming and 

 Utah, he had had the opportunity of seeing a few of the mineral 

 springs which are so numerous and varied in character, west of 

 the Rocky Mountains. 



