190 
rocks. Its place in the arrangement given by Osten Sacken is 
rather at the other end of the series in nearer proximity to the 
Tipuline ; but it may be noticed that in some of the features in the 
neuration of the wing, as in the arrangement in the vicinity of the 
stigma, in which it approaches the ‘Tipulinz, it also shows most 
resemblance to the Limnobini. 
Although Loew referred some amber species to Cylindrotoma, 
Osten Sacken, who has since examined them, says they are all Lim- 
nophilz, so that the species described below, six species of two 
genera, both extinct, are the only ones known in a fossil state. 
CyTTAROMYIA Scudder. 
Cyttaromyia Scudd,, Bull. U. S. Geol. Geogr. Surv. Terr.,iii, 751 (1877); Tere. 
Ins. N. A., 574-575 (1891). 
This genus was founded, in 1877, upon a specimen showing the 
apical half of a single wing, somewhat distorted by folding, and 
rather obscurely preserved, found by Denton among the first known 
tertiary insects of North America, on the lower White River of 
Colorado and Utah. A number of specimens and several species 
of the same genus have since been obtained by me from the same 
spot, while exploring for the U.S. Geological Survey, but no 
further specimens of the same species. ‘The beds at Florissant have 
also yielded several species of the genus and permit a more accu- 
rate and complete account of the generic characteristics. These 
specimens show that my original description was faulty in its inter- 
pretation of the structural elements of the wing: the cells lying 
beyond the ‘‘secondary discal cell’’ were wrongly regarded 
as submarginal cells, for they belong to the ‘‘ posterior ’’ series, 
and all the errors of statement followed from this wrong interpre- 
tation ; but the neuration is none the less remarkable, and, so far as 
I have been able to discover, unique. 
The wings are very long and slender, four or more times as long 
as broad. The auxiliary vein ends in the costa, without any sudden 
curve, at the beginning of thestigma. ‘The first longitudinal vein, 
by very gradually curving downwards, ends in the second, which 
curves upward to meet it, forming a long and slender marginal cell ; 
there is neither subcostal nor marginal cross vein. The second 
longitudinal vein arises near the middle of the wing, varying in the 
species, is generally considerably arcuate at the base, the przefurca 
