SYSTEMATIC ACCOUNT. 85 
Second orbital about one-half third, which is about three-fourths first. Second oral bristle 
over one-half first. Carina broad, flat; face yellowish brown. Cheeks yellow; their great- 
est width about one-fourth greatest diameter of eyes. Eyes clothed with thick pile. 
Acrostichal hairs in six rows; no prescutellars. There are several enlarged hairs in 
front of the two pairs of dorsocentral bristles and in the same rows with them. Mesonotum 
and scutellum slightly shining reddish brown. Pleure yellowish brown above, becoming 
yellow below. Legs yellow. Apical and preapical bristles on first and second tibiz, 
preapicals on third. 
Abdomen, in the male, shining black; basal segments with a narrow yellow posterior 
line, and brownish basally. In the female, the abdomen usually appears largely brown 
in pinned material. In life it can be seen to be yellowish brown, each segment having a 
posterior dark-brown band. 
Wings clear, veins brown. Costal index about 3.9; fourth-vein index about 1.4; 5z 
index about 1.1; 4c index about 0.6. 
Length body 2.5 mm.; wing 2.5 mm. 
Specimens examined: Norway (O. L. Mohr); London, England (E. 
Brunetti); Holland (J. C. H. de Meijere); Barcelona, Spain (J. Arias); 
Montreal (U. 8. Nat. Mus. coll.), Vaudreuil (coll. C. W. Johnson), Rouville 
(coll. C. W. Johnson), Quebec; Franconia (Mrs. Slosson), Hanover (C. W. 
Johnson), Nashua, New Hampshire; Hartland, Vermont (C. W. Johnson); 
Beverley (Burgess), Boston (C. W. Johnson), Amherst (H. H. Plough), 
Fall River (C. W. Johnson), Woods Hole, Siasconset, Massachusetts; 
Kingston, Rhode Island (C. W. Johnson); Meriden, Connecticut (U. 8. 
Nat. Mus. coll.); Niagara Falls (C. W. Johnson), Ithaca (S. W. Frost), 
Nyack (J. L. Zabriskie, 1884), New York, New York; Riverton (C. W. 
Johnson), Princeton (S. Mudd), New Jersey; Maryland, near Plummer’s 
Island (R. C. Shannon); Washington, District of Columbia; Virginia, near 
Plummer’s Island (R. C. Shannon); Atlanta, Georgia (U. 8. Nat. Mus. 
coll.); Kushla, Alabama; Columbus, Ohio (F. M. Webster); Bloomington, 
Indiana (F. Payne); Ann Arbor, Michigan (L. McQuinn); Flat Rock 
(F. N. Duncan), Algonquin (D. W. Coquillett), Illinois; Madison, Wis- 
consin (L. J. Cole); Rochester, Minnesota (A. Weinstein); Lawrence, 
Kansas (E. 8. Tucker); Spearfish, Mitchell (A. Huettner), South Dakota; 
Medicine Hat, Alberta (U. 8. Nat. Mus. coll.); Kaslo, British Columbia 
(R. P. Currie); Moscow, Idaho (A. L. Melander); Pullman, Washington 
(A. L. Melander); Amity, Oregon (D. E. Lancefield); Los Angeles County, 
California (U.S. Nat. Mus. coll.); Mesilla, Beulah (T. D. A. Cockerell), 
New Mexico; Tampico, Mexico (T. E. Holloway); Montserrat, Trinidad, 
West Indies (A. Busck); Perth, West Australia (G. Compere); Sydney, 
Australia (A. Musgrave); Rhodesia (U. S. Nat. Mus. coll.). 
The species is recorded from Porto Rico by Coquillett, but I have been 
unable to find the specimens in the National Museum. It is stated by 
Howard to be recorded from Mauritius. In Europe the species is recorded 
from Sweden and England to Austria and the Canary Islands. 
The eggs and larve were described by Unwin (1907, Trans. Ent. Soc. 
London, p. 285), who also presented data on the habits and on the struc- 
ture of the adult. The eggs have four rather short filaments, as I have also 
observed. The chromosomes, investigated by Metz, and the mating habits, 
are described elsewhere in this paper-(pp. 39 and 6, respectively). A 
brief account of certain mutations that I have obtained will be found 
on page 14. 
This species will breed on fruit of various kinds, and is kept going in 
the laboratory by means of the technique described for D. melanogaster 
elsewhere in this paper. In nature, however, it is not so frequently to be 
found about fruit as are many other species. I have found that stables 
