168 
a distinct though not in any striking way, the table shows that as 
far as the relative numbers of the subordinate groups of the tertiary 
fauna of North America are concerned, our tertiary Tipulide have 
a closer relationship to the fauna of tertiary Europe than to that of 
America to-day. One disturbing element, however, is introduced in 
the great prominence of the Cylindrotomini among the fossils, due 
to the large numbers of the genus Cyttaromyia, which must be 
looked upon as on the whole the most striking feature of the 
tertiary Tipulide of North America. 
As asummary of general results obtained from the careful study 
of these remains, we venture to submit the following propositions : 
1. The general facies of the Tipulid fauna of our western ter- 
tiaries is American, and agrees best with the fauna of about the 
same latitude in America, as far as we are at present acquainted 
with it. 
2. All the species are extinct, and though the Gosiute Lake and the 
ancient lacustrine basin of Florissant were but little removed from 
each other, and the deposits of both are presumably of oligocene 
age, not a single instance is known of the occurrence of the same 
species in the two basins. ‘The Tipulid fauna of the Gosiute Lake, 
however, is as yet very little known, and it should be added that 
the few described species are in no instance the same at Green 
River, Wyo., and White River, Colo., both localities in the same 
ancient lake basin. 
3. No species are identical with any of the few described 
European tertiary Tipulide. 
4. Restricting ourselves to the Florissant basin, from the paucity 
of material in the Gosiute fauna, it will be noticed that a remark- 
able proportion of genera (eight out of fifteen) are not yet * recog- 
nized among the living, these genera including about one third of 
the species. 
5. With one (American) exception—Cladura—all the existing 
genera which are represented in the American tertiaries are genera 
common to the north temperate zone of Europe and America, and 
are generally either confined to these regions or the vast proportion 
of their species are so confined. A similar climate is indicated, 
but this latter conclusion should be received with hesitation, since 
*Tt should be noted here that, in his enumeration of the amber Diptera, Loew recog- 
nized four genera as extinct, of which living representatives have since been found, 
without mentioning those which Osten Sacken regards as Limnophile, 
