318 T. D. A. COCKKRELL. 



Going through the list of insects taken at high altitudes in Ecuador, 

 the following points may be noted. There are four new species of 

 Pterostichus fi'oni 12,000 feet and upwards, but they represent a new 

 subgenus. There is not a single Amara or Harpalus. The two ants 

 from 9000 feet or upwards, are Camponotus sylvaticus and a new 

 Fheidole. Five Satyrinae from 10,000 feet or upwards, are none of 

 them of N. American genera. Pyrameis huniera was taken at 9800 

 feet. There are three species of Lycmna from over 10,000 feet. 

 Three species of Colias are found at 10,000 feet or upwards; one, C 

 alticola Godm. and Salv., being especially characteristic of very high 

 altitudes. 



FOSSIIj insects of COLORADO. 



From the elaborate researches of Mr. Scudder, we have a large 

 mass of facts available concern ng the tertiary insects of Colorado. 

 As in the case of the living Andean fauna, we can detect no marked 

 resemblance to the species now inhabiting the Rocky Mountains; 

 and the indications are, that the recent fauna has not been derived 

 from that preserved in the beds at Florissant and elsewhere. So far 

 as modern genera are represented, they are certainly not alpine, but 

 indicate a climate more like that of the Southern States. 



Mr. Scudder's recent paper (Proc. Bost. Soc. N. Hist. 1892) on 

 the Tertiary Rhynchophora brings out the facts of the case very 

 clearly. The Gosiute fauna, from western Colorado, differs greatly 

 from that of Florissant, no species being common to both ; and of 

 ninety-seven genera, only eighteen are common to the two faunje. 

 Yet these had hitherto been considered as belonging to about the 

 same age. 



All the species are extinct, and no species is identical with any 

 European tertiary form. Many of the genera are extinct; existing 

 genera are not infrequently now subtropical or tropical. There are 

 no extinct families, but in one instance an extinct subfamily with 

 numerous representatives. 



Almost exactly the same results were obtained previously from a 

 study of the tertiary Hemiptera, though at that time much less ma- 

 terial from the Gosiute was available. 



THE GLACIAL EPOCH. 



In order to account for the facts above cited, it is necessary to con- 

 sider the geological history of America. In Prestwick's " Geology" 

 (1888) there is a good account of what is known about the glacial 



