oO Proceedings of the Biological Society of ]V(ts/nngton. 
Sapromyza similata sp. nov. and S. compedita Loew. 
S. similata may he characterized as I'ollows: 
^^ale .—Yellow suho})aqne: only the second joint of hind tarsus and 
apices of the last three hind tarsal joints hlack. Win;^s with cross veins 
distinctly and broadly infnscated, a fuscous spot at end of marginal cell, 
which is generally connected with a spot helow it on the third vein, and 
another spot of same color at a])ex at third vein, the spot on middle of 
last section of third vein is always separated from the s[)ot enclosing the 
outer cross vein and distinctly nearer to the wing ti]). 
The arista is very indistinctly puhescent; the mesoiu'tum has 4 dorso- 
central bristles, the anterior one very weak, and situated jnst in front of 
suture; the forwardly-directed ventral a]q:>endages of the hypopygium 
have a very distinct rounded incision at about their middle which, when 
they lie together, presents a large rounded opening, and the hairs at a])ices 
of these organs are of irregular lengths, one of them being esirecially long; 
the hind tarsus is elongated, the basal joint slender, the second joint flat¬ 
tened, but distinctly longer than broad, the apices of the next three joints 
distinctly over half as broad as the apex of the second (Fig. 4) ; hind tibia 
slightly thickened and without any noticeable ventral hairing; last sec¬ 
tion of fourth vein distinctly longer than the penultimate section (Fig. 2). 
Female. —Similar to the male in color and chaetotaxy. The hind tarsus 
has the second joint very little thickened. (Figs. 2, 4, and 17 illustrate 
similata .) 
In Sapronijiza compedita Loew the male is similar in color and in the 
number of wing marks to the above, but the spots in marginal and sub- 
marginal cells are more distinctly coalescent and are almost invariably 
connected with the cloud on the posterior transverse vein. 
The arista is distinctly haired; the mesonotum has normally only three 
])airs of dorsal-ceiitrals, the anterior weak pair of similata being absent; 
the ventral organs of hypopygium have a much smaller internal excision, 
causing the opening, when they lie together, to be very small in compari¬ 
son with that in the previous species, and the apical hairs on those organs 
are less conspicuously irregular than in that species; the second joint of 
the hind tarsus is very much liattened, ahnast disc-like, and as broad as 
long, the apices of the remaining joints of hind tarsus are not nearly half 
as broad as apex of second (Fig. 5); hind tibia with several loo.se, soft 
hairs on the apical fourth of the ventral surface; last section of fourth 
vein e(iual to, or slightly shorter than, penultimate section. (Fig. b.) 
Female. —Similar to male in color and chaetotaxy. The hind tibia is 
devoid of the ventral hairs, and the second joint of the hind tarsus is 
barely broader than the next joint. (Figs. 5 and (i illustrate compedita 
Ivoew.) These species are very close to each other, but may be readily 
separated by the characters given in the above summary. 
I have before me nine specimens of shnilata from Algonquin, Illinois 
(Nason); one female (the tyi)e), St. Joseph, Illinois; one female, Quincy, 
Illinois, swept on sand bar, August 12, LS8() (C. A. Hart); one male, 
(Michigan; one female, (Merchantville, New Jersey; one female, swept 
