773 
No 145.] 
ending in an oval knob) yellowish white. Abdomen dusky, clothed with a short 
black beard, hind edges of the segments pale dull yellow. Legs pale yellow, with a 
fine black beard, and the spine-like bristles at the end of the shanks black. Winge 
iridescent, smoky brown on the outer and apical margins, hyaline towards the axilla, 
the space between divided into numerous square hyaline spots by dusky longitudinal 
stripes, one strips being placed in the middle of each dell and sending short, trans¬ 
verse branches to the veins at regular intervals; veins and veinlets black. 
Nearly related to the flies which we have been considering are 
those very singular ones, called Stem-eyed flies from having 
straight horn-like processes extending outwards from the sides of 
the head, upon the ends of which the eyes are inserted. These 
form the old Linnsean genus Diopsis. About a dozen species are 
known, all inhabiting tropical Africa and the East Indies, with 
one exception—the Short-liorned Stem-eye of this country, origi¬ 
nally described by Mr. Say under the name of Diopsis brevicornis. 
As this species has the tubercles on which the eyes are inserted 
quite short, their length being less than their breadth, whilst Id 
the other species they are much longer and cylindrical, Mr. 
Say, in the third volume of his American Entomology, plate 52, 
proposed for it a distinct genus, which he named Sphyracephala. 
The European entomologists, however, ignore this genus and con¬ 
tinue to arrange our species in the old genus Diopsis. I ana 
somewhat surprised at this. A specimen from Senegal, ticketed 
D. thoracica by Macquart, for which and numerous other speci¬ 
mens of Diptera I am indebted to M. Bigot, of Paris, indicates 
the foreign species of this tribe to be quite unlike ours in their 
general appearance. Having recently taken a second species 
closely related to the brevicornis, I think our two American 
species must be ranked as generically distinct from those of the 
old world. In addition to the extreme shortness of the ocular- 
protuberances and the minuteness of the projecting points to the 
scutel and on the sides of the thorax towards its base, they are 
further distinguished by having an anastamosis between the cos¬ 
tal or anterior marginal vein and the sub-marginal or short vein 
which runs into the anterior margin near the middle, this anas¬ 
tamosis taking place a short distance before the two veins unite. 
In the new species which I have alluded to a dusky spot or short 
band extends from this anastamosis across the two basal cells of 
the wiug, and a second band half way from this to the tip 
