1925 ] New Species of North American Dolichopodidce 
181 
Hydrophorus criddlei sp. nov. 
Male : Length 3-3 . 2 mm. ; of wing 4 . 2-4 . 7 mm. Face rather 
wide, silvery white, the green ground color shows through a little 
on upper third, lower portion a little longer than wide, evenly 
rounded on its lower edge. Palpi black with white pollen, which 
is not silvery, covered with delicate pale hairs and with several 
stouter, black, very short ones. Antennae black, third joint 
rounded at tip. Front opaque brown. One pair of postverticals; 
the black orbital cilia extend down to the middle of the eye. 
Beard rather bright yellow, quite long, there are several black 
bristles under the neck. 
Thorax green, dorsum nearly opaque with brownish pollen; 
pleurae with thin brown pollen; propleura with one long black 
bristle and a few pale hairs above fore coxa; acrostichal bristles 
small, reaching nearly to the front of the thorax; dorsocentrals 
moderately large; scutellum with four marginal bristles. Ab- 
domen green with white pollen on the sides, its hairs mostly 
black, only a few very small white hairs on the sides and at tip. 
Hypopygium mostly concealed, it has a small black appendage 
projecting below and the posterior edge of fourth abdominal 
segment also extends downward a little in the center of its ventral 
surface. 
Coxae black; anterior pair with white pollen and long, but 
not very abundant, yellow hair on the front surface, these hairs 
become a little shorter towards the apex, I cannot see any black 
spines, even at tip. Femora and tibiae green; fore femora thick- 
ened at base, tapering to the tip, they have a row of five black 
spines on lower surface of basal third, three of which are as long 
as the thickness of th° tibia, the two nearest the base shorter, 
there are also many long pale hairs on the lower surface, these 
are longer than the spines and extend from the base almost to 
the tip, where they are shorter and further apart. Fore tibiae 
with a row of spines extending their whole length. Middle 
femora towards the tip and middle tibiae with two or three very 
slender, but rather long bristles on the anterior surface. Tarsi 
black, plain. Joints of fore tarsi are as 30-16-13-9-11; those of 
middle pair as 41-20-15-10-12; joints of hind tarsi as 38-26-18-12- 
