ENTOMOLOGY OF COLORADO. 317 



(3.) Area of Hemj)hitlia -\- Prophysao)i, -\- Amalia, etc. = Washington, Oregon 

 and part of Idaho. 



(4.) Area of Ariolimax -\- Prophysaon -\- Phenacarion. etc. = Piijient Sonnd dis- 

 trict and into Oregon. 



(5.) Area of Ariolimax + Prophysaon -\- Agriolimax -\- Hesperarion + Amalia = 

 Oregon and California, along the coast. 



(6.) Area of Auadenulus, etc. = Cuyamaca Monntains, California. 



(7.) Area of Binneya = Sta. Barbara Island, California. 



These areas cannot in evei'v case be precisely defined, owing to 

 lack of information ; but their utility seems to lie chiefly in the fact 

 that they give results quite independent of any previous opinion or 

 bias on the part of the collator. 



ORIGIN OF THE ROCKY MOUNTAIN FAUNA. 



The numerous fossils of Colorado bear testimony to the fact that 

 the region of the Rocky Mountains has in the past been peopled by 

 a highly remarkable and numerous fauna. This fauna, however, 

 does not appear to be ancestral to that of the present day. Nor has 

 the present fauna any special connection with that of the high re- 

 gions to the far South — the Andes. In order to arrive at just con- 

 clusions, it will be needful to consider these ])oints in some further 

 detail. 



ALPINE INSECTS OF THE ANDES. 



The recently-published "Supplementary Appendix" to Mr. 

 Whymper's work on his travels amongst the Andes of Ecuador, 

 containing an account of his captures, includes some very valuable 

 information about the insects of high altitudes in that country. The 

 late Mr. H. W. Bates has written the introduction, in which the 

 following passages occur: 



"If there had been any distinct element of a North Temperate or South Tem- 

 perate Coleopterous Fauna on the Ecuadorian Andes the collections be made, 

 inexhaustive though they may be, would have sliown some traces of it ; but there 

 aie none. A few genera belonging to temperate latitudes, though not found in 

 the tropical lowlands, do indeed occur, but they are forms of almost world-wide 

 distribution in similar climates, and there is no representative of the numerous 

 characteristic and common genera of the North or South. Even the Northern 

 genera, more or less abundantly found on the Mexican highlands, are absent." 



" One feature of the fauna is of great interest. It is the occurrence of apter- 

 ous species of genera which at lower levels are always winged." 



" It seems to me a fair deduction from the facts hei'e set forth that no distinct 

 traces of a migration during the lifetime of existing species, from North to South, 

 or vice versa, along the Andes, have as yet been discovered, or are now likely to 

 be discovered." 



TRANS. AM. ENT. SOC. XX. NOVEMBEK, 1893. 



