48 PSYCHE [April 



served for us in the rocks and shales, so that we are given a point from which to 

 begin our investigations. Perhaps the Tertiary deposits in Wyoming and Colorado, 

 though including but a mere fragment of the vast host of insects that must have 

 been entombed in the rocks, have yielded us the greatest amount of information 

 relative to the ancient fauna of America, containing as they do, and in profusion, 

 not only representatives of every order of insects known to-day, but types of every 

 dominating family which at present exists. We have also been further fortunate in 

 . having so faithful a student as Mr. S. H. Scudder to study this material, for it con- 

 tains not only numberless bodies of the more stable insects like the Coleoptera, but 

 even those of Aphididae and microscopic parasitic insects, whose bodies are of the 

 most fragile nature. We are thus put in possession of facts that go to show that, as 

 to-day, the aphides were probably in part viviparous, and we have besides the spe- 

 cial sexual forms of the ants and the triungulin larva of the Meloe thus preserved 

 for us. A study of this material has given us some surprising facts. Among the 

 most significant, and quite apropos to our subject, is the fact that a careful inves- 

 tigation of the Rhynchophora obtained, as compared with the forms now existing in 

 this country, shows that the recent American Rhynchophorous fauna agrees better 

 in its broad features with the Tertiary fauna of Europe than with the Tertiary fauna 

 of America. Though possibly a little in advance of its proper place, it may not be 

 entirely out of order to call attention here to a fact well known to entomologists 

 and especially to lepidopterists ; viz., that where a species is found both on the 

 Atlantic and Pacific slopes, and which also occurs in Europe, individuals taken 

 from the Pacific coast region are more nearly like those found in Europe than are 

 those found along the Atlantic coast. In a list of Coleoptera common to both 

 this country, northern Asia, and Europe, published by the late Dr. John Hamilton, 

 in 1889, 487 species were enumerated, and an almost immediate revision of this 

 paper by the Swiss entomologist, M. Alfred Fauvel, added eight more to the list. 

 In these lists, however, no distinction was made between such as were introduced 

 in articles of commerce and such as came in a strictly natural manner. Thus it 

 will be seen that even in Tertiary times, as also in our recent past, there has been a 

 close relationship between the insect fauna of North America, northern Asia, and 

 Europe. 



Geologists are in possession of sufficient data to show conclusively that, during 

 some period of the world's history, the region about the Arctic circle enjoyed a cli- 

 mate as temperate as we have at the present time, while the region now included in 

 the northern United States abounded in tropical animal and vegetable life. Thus 

 there might have been, and probably was, a free intercourse between North America 

 and northern Asia via the northwest, and, possibly, with Europe via the northeast ; 

 but of this last we are not so certain. At present, while insects from the eastern 



