209 
cell, but by no means so much so as in the living species. The 
discal cell is long and rather slender, widening apically and as long 
as the third posterior cell. The great cross vein strikes the fourth 
longitudinal vein at some distance short of the discal cell. The 
legs are very slender and the fore tarsi of excessive length. 
Length of wings, 6.5 mm.; fore femora, 5.25 mm.; tibia, 5.5 
mm.; tarsi, 10.5 mm.; mid femora, 5.75 mm.; tibiz, 6 mm. ; 
tarsi, 6.25 mm. ; hind femora; 6 mm. 
Florissant, Colorado. One specimen, No. 215. 
Tribe ERIOPTERINI. 
Of this tribe five genera and eighteen species, including those 
described below, are known in a fossil state. Only three species of 
as many genera—Erioptera, Gnophomyia, and Gonomyia—have 
been described from the European rocks, but eight species of Eri- 
optera are said by Loew to occur in amber. Gonomyia has four 
species in America, and Cladura has two, while a single other 
species has been referred to a distinct genus, Cladoneura, closely 
allied to the last. 
Gonomyia Megerle. 
Gonomyia Meg., in Meig., Syst. Beschr. eur. 2weifl. Ins.,i, 147 (1818). 
This is a north temperate genus, the known existing species being 
confined to Europe, which has eleven species, and eastern North 
America, which has five. It has before this been found fossil, the 
species described by Heyden in the Aquitanian of Rott in Rhenish 
Prussia under the name of Limmnodia sturt, being certainly a Gono- 
myia. But in this country it is found fossil more abundantly, for to 
this genus belong four nearly allied species from Florissant with 
very characteristic neuration. Except that the auxiliary vein is 
relatively long and the marginal cell slender, they do not appear to 
differ in any common characteristics from modern forms. The 
species may be separated thus: 
Table of the Species of Gonomyta. 
Preefurca with little or no basal arcuation, nearly straight throughout. 
Base of first submarginal cell lying scarcely beyond the tip of the first lon- 
gitudinal vein. 
PROC, AMER. PHILOS. SOC. XXXII. 148. 24. PRINTED JAN. 17, 1894. 
