FAM. EMPIDID/E 91 
Type species : S. eremita, Becker (Pl. 7, Fig. 62). This genus was proposed by Becker for 
a whitish pruinose Egyptian fly occurring on the sands of the seashore. At first sight its whitish color, 
light colored legs and pure white bristles were far from suggesting the black species of Microphorus, but 
as recently a white haired Microphorus and a black Schistostoma have been found, Becker (1909) concluded 
that ScAistostoma is but a subgenus of the older Microfhorus. 
SYNOPSIS OF THE NORTH AMERICAN SPECIES OF MICROPHORUS 
r. Middle trochanters of the males with one or two strong spine-like 
bristles, middle femora cf with some long stiff flexor bristles, 
middle tibize c more or less excised within before the tip; acrosti- 
chals biseriate; fifth ventral cf with apical spines. . . . . HO AE ARR LL "P cu E CIR 
Middle trochanters and femora not armed beneath with long stiff 
bristles, middle tibiz straight; fifth ventral not with projecting 
BDIBeSS - à RATE ; ; ope qo T UN 
2. Hind tibie c clavi aM strongly veciliio: hind metatarsi ig iac 
Eon s HDOUEO IDE s ers cU DE I D xr ei o iwpeesee uu. Uu 3. 
Hind tibia not clavate and not strongly pectinate, hind metatarsi not 
swollen; size about 2 mm. . . . . : A Wuco dM eri C NIU Ed 
3. Fourth and fifth ventrals cf each with ivicale spines; middle jetibià 
cf with five or six flexor bristles; halteres yellow. . . . M. ROBUSTUS, nov. sp. (t1). 
Fifth ventral c with apical spines; middle femora c with two diii 
bristles and one sub-basal arising from the anterior side, hind 
metatàrsi Cf pectinate above, halteres black . . . . . . . M. anwiPES, nov. sp. (2). 
4- Third antennal joint conical, as long as its arista; middle femora Qc 
with a group of three strong flexor bristles, inner side of middle 
tibia c with a bristly callous at three-fifths the tibial length; 
female CIUPreons "dc ou NALE ADONA HOD s lc rov 1. M. RAVIDUS, Coquillett. 
(1) Microphorus robustus, nov. sp. — Male. Length 3 mm. Black, coated with opaque brown pollen, 
halteres brownish yellow. Upper facets enlarged ; third joint of the antennze one-half longer than deep, conical with concave 
sides, no constricted process, arista twice as long as the third joint ; mouthparts not projecting. Thoracic bristles rather 
sparse, acrostichals biseriate, five pairs in number, about nine dorsocentrals, all but the last two short, two posthumerals, 
two small supra-alars, four scutellars. Hairs of the abdomen moderately long and black, fourth and fifth ventral segments 
with a double spine-like bristle on each side of the apical margin, pygidium rather small, twisted. Middle trochanters with 
à stiff double bristle, front femora with fine long cilia below, middle femora with about six spinous flexor bristles, hind 
femora with short pectination above and below, middle tibia distorted on the apical half, the inner side broadly excised, 
hind tibiae clavate and exteriorly pectinate, hind metatarsi globose but not pectinate. "Wings dark, stigma distinct, sections 
of the fourth vein proportioned 1 : 2 : 3, of the fifth vein equal. 
"Type received from E. T. Cresson, Jr. and deposited in the Philadelphia Academy of Science. Swarthmore, Penn- 
sylvania, June rz, 1909. 
(2 Microphorus armipes, nov. sp. — Male. Length 2.9 mm. Black, including all the appendages. Upper 
facets of male enlarged ; third joint of the antenne suddenly constricted beyond the base, the constricted portion as 
long as the basal portion, arista twice as long as the third joint ; mouthparts not projecting. Mesonotum lightly coated 
with brown, subshining, bristles long. the acrostichals biseriate, about seven pairs in number, eight to ten dorsocentrals, 
one posthumeral, two supra-alar, four scutellars. Abdomen subshining, its hairs sparse, long and black, fifth ventral 
with four apical spinous bristles; pygidium twisted, penis furcate. Middle trochanters with a double long stiff bristle 
front femora pectinate below, hind femora pectinate above and below, middle femora with two long strong flexor bristles, 
near the middle, the distal one blunt and shorter than the proximal, a shorter subbasal bristle arising from the anterior 
side, hind tibi; clavate, strongly pectinate along the extensor edge, hind metatarsi swollen and likewise pectinate. 
Wings darkly infumated, stigma distinct, sections of the fourth vein proportioned 1r : 2 : 3, of the fifth vein equal. 
Female. Bristles short, legs not pectinate nor spinose. 
Several specimens from Quilcene, Olga and Seattle, Washington, the last mentioned received from Professor 
Kincaid 
