169 
our knowledge of the distribution of American genera is mostly 
confined to the Atlantic States. There are, however, no certain 
indications of a warmer climate, such as have been shown from the 
study of other groups. 
6. There are no extinct groups higher than genera, but one or two 
of these, such as Cyttaromyia and Micrapsis, are of a somewhat 
striking character. 
7. The relative importance of the two subfamilies of Tipulidz, 
though differing on the two continents of Europe and America both 
in tertiary and in recent times, was much the same, on each con- 
tinent, in tertiary times as now; while in the relative preponder- 
ance of the different tribes of Limnobine, our tertiary fauna shows 
a somewhat closer agreement with the European tertiary than with 
the existing American fauna. There are, however, no striking 
generic alliances pointing in the same direction. 
The above general conclusions have been reached after as careful 
a study of the tertiary fauna of Europe as the literature would allow, 
it being unfortunately necessary to depend entirely upon published 
materials, most of them ancient, for any conclusions regarding the 
European fossils. Fortunately, the way has been lightened by oc- 
casional expressions of opinion from Baron Osten Sacken, who has 
personally examined not a few of them and published here and there 
valuable statements regarding them. Being compelled to subject 
all the literature of the subject to a careful scrutiny in order to ob- 
tain any proper glimpse of the known tertiary fauna of Europe, it 
has seemed best to publish in this connection a formal historical 
review of the European tertiary Tipulide, in order that the grounds 
of my general statements may be better understood. 
Accordingly, in the next section of this memoir, I give such a 
review, following it with a summary of results in the form of an 
Alphabetical List of the Genera and Species ; and again witha Tabu- 
lar View of Tertiary Tipulidz in general, systematically arranged ; 
and add a note on Pretertiary Tipulidez, before proceeding to a 
special and detailed systematic discussion of the American Tertiary 
Tipulide. 
II. HisrortcaAL ACCOUNT OF THE EUROPEAN TERTIARY TIPULIDA, 
WITH COMMENTS. 
The first fossil Tipulidze described are those mentioned by PRESL 
in 1822 (Del. Prag.), purporting to have come from amber. They 
PROC. AMER. PHILOS. SOC, XXXII. 143. V. PRINTED JAN. 5, 1894. 
