PHORIDAE FROM PARAGUAY. 
441 
ments are entirely covered with bluish-white, iridescent pollen, except 
for narrow opaque black posterior margins. 
It is therefore, probably only a well-defined color variety. 
Gymnophora Macq. 
Up to the present writing this genus has remained monotypical, 
represented by G. arcuata Meig. first described as a member of the 
European fauna, 1 and the later recognized from the United States 
by Osten Sacken in 1878 (Cat. Dipt. N. Amer. Smithsonian Mise. Coll., 
p. 212). It is therefore of considerable interest to know that the genus 
is represented in Paraguay by a second species of which there are two 
specimens in the small collection before me. 
As will appear from the following detailed description, the South 
American form is quite different from the European arcuata , but is 
without doubt congeneric as it presents all the generic peculiarities of 
the typical species except for slightly less reduced frontal bristles. 
In this connection, I have been led to compare closely Nort 
American specimens of arcuata with those from Europe to make sure 
of their identity. A single example from the Pacific Coast (Tacoma, 
Wash.) is not distinguishable from others collected in Germany, but 
all the specimens from the eastern United States which I have at hand, 
show slight but constant differences in the wings. They lack a slight, 
but very distinct swelling of the costa just before the tip of the first 
vein, which meets the costa nearer to the base of the wing than in 
European examples, where its tip is opposite the furcation of the third 
vein. Further material is necessary, however, to show that individuals 
from the eastern United States are really distinct from the European 
and Pacific Coast form. If such should prove the case, it will not be so 
surprising, since many palæarctic insects appear in Western North 
America and not in the Atlantic Eegion. 
Gymnophora colona n. sp. 
Female. Length 1*5—1*8 mm. Black, shining on the head and 
thorax; legs yellowish brown, darker on the posterior pair; wings in- 
fuscated. Front shining, not punctate or pollinose, but sparsely hairy ; 
occipital row of bristles with the lateral bristle quite well developed, 
but with the median pair shorter. Lateral bristle of next row below also 
1 Meigen, Syst. Besclir. zweifl. Ins., VI, p. 222, 1830. 
