70 THE NORTH AMERICAN SPECIES OF DROSOPHILA. 
38. Genital arch of male with a hook-like posterior process (fig. 13); cheeks relatively 
rive y cru Oy fk (01 ee: 159) DR ORR Aa EON RE  PimeT  cae GT DNR MAES iD. | melanogaster (p. 89) 
Genital arch with a clamshell-like posterior process (fig. 14); cheeks broader 
(ct (0) Lies en rae Ma uP he meee nia Seni Aihcdeee NM ALAA A OF CANOE YES ....stmulans (p. 91) 
39. First oral bristle not twice second; not found in flowers............. funebris (p. 84) 
First oral bristle over twice second; live in flowers...................0ceeeee- 40 
40) (Browns: costalingex Over Oye a0 c\ idee) sete tly faire han oc te ae eer Ls a alfart (p. 75) 
Blacks costal mdexcumder 3.0) acyic5 yk an ea Cet ee One aha tristant (p. 75) 
Not included in the above key: illota (p. 80). 
For purposes of description, the species of Drosophila listed below have 
been separated into several groups. Of these the first three, typified by 
D. sigmoides Loew, D. flore Sturtevant, and D. dubia n. sp., respectively, 
are fairly distinct. They might be separated as new genera if one were 
inclined to multiply generic names. Perhaps the first two might be united 
to form a single new genus. The groups typified by D. lutzii Sturtevant 
and by D. prognatha Sturtevant, respectively, are also fairly distinct, but 
are harder to define satisfactorily than are the first three. Among the 
miscellaneous species, D. opaca Williston and D. superba Sturtevant are 
quite unusual, and each of these might serve as the type of a new genus if 
one were so inclined. D. calloptera Schiner and D. guttifera Walker are 
scarcely less anomalous. The other species, I think, may safely be con- 
sidered as typical congeners of D. funebris Fabricius, the type. I have 
been unable to even make a satisfactory arbitrary division of them into 
groups. 
Group A. 
Prescutellars present; wings clouded; slender species; bristles and hairs brown; not 
frequenters of fruit. 
Drosophila sigmoides Loew. 1872. Berlin. ent. Zeit., 16, 102. 
o, 2. Arista with about four branches above and three below. Antenne yellow, 
third joint brown. Front over one-third width of head, wider above; brown. Second 
orbital about one-half other two. Second oral bristle less than half length of first. Carina 
broad and flat; face yellow. Clypeus prominent. Cheeks yellow; their greatest width 
about one-sixth greatest diameter of eyes. Eyes with short, fine pile. 
Acrostichal hairs in six rows; prescutellar bristles well developed. Mesonotum reddish 
brown, grayish yellow between the dorsocentral rows. Scutellum grayish yellow. Pleurze 
grayish brown. Legs yellow. Apical and preapical bristles on first and second tibiz; 
preapicals on third. Bristles and hairs brown. 
Abdomen dull brown, no markings visible. 
Wings grayish, darker along anterior margin; blackish at tips of second, third, and 
fourth veins and on both cross-veins. There is usually a clear spot between the second and 
third veins, and another between the third and fourth. Posterior cross-vein distinctly 
sinuate. Costal index about 4.0; fourth-vein index about 1.5; 5x index about 1.0; 4c 
index about 0.7. 
Length body 2.3 mm.; wings 2.5 mm. 
Specimens examined: Cold Spring Harbor, New York (C. W. Metz); 
Algonquin, Illinois (D. W. Coquillett); Plummer’s Island, Maryland (A. K. 
Fisher); Falls Church (Nathan Banks), Diggs (R. C. Shannon), Virginia; 
St. Elmo (near Chattanooga), Tennessee (W. S. Adkins); North Carolina 
(U. 8. Nat. Mus.); Pickett Springs (near Montgomery, F. E. Watson), 
Gulferest, Kushla, Alabama; Plano (E. S. Tucker), type locality (Loew 
material), Texas. 
I have collected this form in southern Alabama by sweeping grass and 
weeds. Attempts to get it to breed on fruit have not been successful. It 
was not attracted to fruit that was exposed for several days in a small patch 
of young plants of Solidago canadensis, from which D. sigmoides could be 
swept at any time. The specimen from New York, however, was collected 
by Dr. Metz on windfall apples. 
