196 
Named for Baron C. R. von Osten Sacken, without whose studies 
on recent Tipulide, the investigation of the fossil American forms 
would be attended with far greater difficulty. 
Tribe LIMNOBINI. 
This is one of the dominant tribes of Limnobinz, whether now 
or in past times. Five genera and more than thirty fossil species 
are known, the only extinct genera being two—Spiladomyia with 
one, and Limnocema with four species, all found in North Ameri- 
can rocks. Dicranomyia is shared about equally between the Col- 
orado tertiaries and the Baltic amber, while Geranomyia and Lim- 
nobia are known only from Aix and other European deposits, the 
latter genus in considerable numbers. 
DICRANOMYIA Stephens. 
Dicranomyia Stephens, Catal. Brit. ins., 243 (1829). 
This genus, according to Osten Sacken, probably occurs in 
all parts of the world, although it may be principally at home in 
the more temperate latitudes. It appears to have been well 
developed in our tertiaries, and occurs in equal abundance in the 
European. The eight fossil European species, still unpublished, all 
come from amber, and were referred by Loew to a new genus, 
Ataracta, which Osten Sacken says is ‘‘ apparently synonymous with 
Dicranomyia.’’ In this country, besides the three species already 
described by me from the lower White River of Colorado and 
Utah (and to which two of the species described by me as Tipule 
must probably be joined) the U. S. Geological Survey has two 
others from the same locality, and five are described below from 
Florissant. The described species may be separated by the follow- 
ing table: 
Table of the Species of Dicranomyia. 
Marginal cell shorter than the breadth of the wing. 
Distal portion of marginal cell almost as long as the proximal. 
Larger species, with wings about 7 mm. long............... longipes. 
Smaller species, with wings but little more than 5 mm. long. 
stagnorum. 
Distal portion of marginal cell much shorter than the proximal. 
