210 
Small species. Tip of auxiliary vein lying much less than half way 
from the origin of the second to the origin of the third longitudinal 
VSL a) 275) Srevastte colts otahor. se tonte Crt ac T SAT a hee eee rae eet profundi. 
Large species. Tip of auxiliary vein lying much more than half way 
from the origin of the second to the origin of the third longitudinal 
MELD sic spate n ah gies Creprel teeter eeetan el nee 2 eee eee ae labefactata. 
Base of first submarginal cell lying distinctly beyond the tip of the first lon- 
m@itudinaldvieiniy ty. clack its cm ericiae ninleie ter: ASS primogenitalis. 
Pretures wath strong areuation at, basen sees asie ser ee oe oe ee ee frigida. 
Gonomyia profundi. 
1A Sh toed Ge 
The wings are hyaline. The auxiliary vein ends barely before 
the middle of the wing and a little distance beyond the origin of 
the preefurca, the subcostal cross vein appearing to lie midway 
between the two. The first longitudinal vein ends in the costa 
opposite the middle of the discal cell. The przfurca is long, 
nearly straight, arises at the end of the basal two fifths of the 
wing, and is considerably more than half as long as the rest of the 
vein. The oblique upper branch of the second longitudinal vein 
arises opposite the tip of the first longitudinal vein, making the 
first submarginal cell more than half as long as the second; the 
latter is considerably longer than the first posterior cell, and 
the second and third posterior cells twice as long as the discal cell, 
which isclosed. All the veins running longitudinally are gently and 
uniformly arcuate. 
This is the smallest of the fossil species of the genus. 
Length of wings, 5 mm. ; fore femora, 2.75 mm. ; tibiz, 2.75 
mm. ; mid femora, 3 mm.; tibiz, 3 mm.; hind femora, 3 ? mm. ; 
tibiz, 3 mm. ; tarsi, 3.25 mm. 
Florissant, Colorado. One specimen, No. 7461. 
Gonomyia labefactata. 
BlAricnAs 
The wings are hyaline, without trace of color except the luteous 
veins, which appear to be a little thickened in certain parts, 
especially the fifth longitudinal vein ; there is no trace of a stigma. 
The auxiliary vein terminates at a remarkable distance beyond the 
origin of the preefurca, reaching nearly to the base of the third 
longitudinal vein, and well beyond the middle of the wing, the 
