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INTRODUCTION. (6 
tained are but four, if we except a couple of beetles, Otiorhynchites fossilis, 
found at Fossil, Wyoming, and Hylastes squalidens, from the Pleistocene 
beds of Searboro, Ontario. ‘These four localities are Florissant in central 
Colorado, the crest of the Roan mountains near the head of East Salt creek 
in western Colorado, the buttes bordering the White river near the Colorado- 
Utah boundary, and Green river city, Wyoming. All of these localities, 
except the Roan mountains, were described in more or less detail in my 
Tertiary Insects of North America. The Roan mountain beds are appar- 
ently merely an extension of those found on the White river, 50 miles dis_ 
tant, but here confined to the very crest of the range. Fossil insects are 
found at several points, but only in one spot have they been obtained in 
any remarkable number; here, however, in extreme abundance. As this 
spot was 5 miles distant from our camp and our time and supplies were lim- 
ited, no great number of specimens were brought away, but enough was 
seen to warrant the belief that a prodigious number of specimens might be 
obtained there. 
The detailed study of the fossil Rhynchophora has made very clear and 
specific one point which impressed me in general while working in the 
field, and that is the wide difference between the character of the fossils 
obtained at Florissant and those obtained at any of the other localities 
(perhaps excepting Elko, Nevada, of which little is known) in the Rocky 
mountain region. The Hymenoptera which abound at Florissant almost 
disappear in the other localities, while the Coleoptera, which hold a third 
place at Florissant, form the larger proportion of the mass in the other 
deposits. To test the opinion formed by the cursory examination of speci- 
mens in the field, I have counted the specimens obtained in each of the 
different localities visited during a single summer, and find the opinion 
amply confirmed. 
The first set of columns in the accompanying table shows the total 
number of specimens (regardless of species) obtained during this season’s 
work, separated by orders, (1) in all localities; (2) at Florissant alone; and 
(3) in the other localities, excluding Florissant; and the second set of 
columns the same figures reduced to percentages. Nothing could well be 
more striking than the contrasts in the Hymenoptera and Coleoptera. 
