SYSTEMATIC ACCOUNT. 87 



wider above; reddish yellow, orbits and triangle grayish. Second orbital about half the 

 third, which is scarcely over half the first. Carina quite narrow, confined to the upper part 

 of the face. Face and cheeks yellow. Second oral bristle scarcely half the first. Greatest 

 width of cheeks about one-sixth greatest diameter of eyes. Eyes with short, fine pile. 



Acrostichal hairs in six rows; no prescutellars. Mesonotum and scutellum dull yellow- 

 ish-brown. Pleiu-ae yellow, brownish above. Legs pale yellow. Apical and preapical 

 bristles on first and second tibise, preapicals on third. 



Abdomen yellow, each segment with a dark-brown posterior band that is wider in the 

 mid-dorsal region. 



Wings clear. Costal index about 3.8; fourth- vein index about 1.4; 5x index about 1.2; 

 4c index about 0.9. 



Length of body 2.3 mm. ; wing 2.5 mm. 



Specimens examined: only the types; Flat Rock, Illinois, 1915 (Dr. F. 

 N. Duncan). Labeled "Fungus." 



Drosophila verticis Williston. 1896. Trans. Ent. Soc. London, 413. 



" 9 . Front very broad above; yellow, the vertical stripes and a stripe or spot near 

 the orbits, metalUc-blue ; lower part of the front wholly yellowish. Antennae yellow, the 

 third joint brown; arista with long rays above and below. Face yellow, flat, not carinate. 

 Mesonotum shining reddish-yellow; scutellum opaque brown on its upper surface. Pleurae 

 more brown. Abdomen apparently yellow, with brown posterior bands to the segments. 

 Legs yellow. Wings nearly hyahne; third section of the costal vein two-thirds or more 

 the length of the second section; anal cell incomplete, the vein closing the cell outwardly 

 indistinct or wanting. Length 2 mm. 



" Two specimens. St. Vincent." 



I have not seen this species, so have reproduced Williston's description 

 verbatim. 



Drosophila nana Williston. 1896. Trans. Ent. Soc. London, 416. 



Arista with, about five branches above and two or three below. Antennae yellow, third 

 joint brownish. Front wider above; reddish brown, paler below. Only one conspicuous 

 oral bristle. Carina small, low, confined to upper part of face; face yellowish brown. 

 Palpi brown. Eyes with fine, sparse pile. 



Acrostichal hairs in six rows. Mesonotum reddish yellow, shining, pleurae darker. 

 Legs yellow. 



Abdomen black, shining. 



Wings clear. Costal index about 1.8; fourth- vein index about 1.8; 5x index about 1.2; 

 4c index about 1.6. 



Length body 1.8 mm. 



The above description was drawn largely from my fragmentary notes 

 on a specimen in the United States National Museum that agrees with 

 Williston's description. A few points not included in those notes have 

 been added from the original description. 



Specimen examined: Tabernilla, Canal Zone, Panama (A. Busck). 

 Described from St. Vincent, West Indies. 



Drosophila sororia Williston. 1896. Trans. Ent. Soc. London, 412. 



Arista with only a few rays. Antennae yellow. Front over one-third width of head, 

 wider above. Second orbital one-fourth size of other two. Only one prominent oral bristle. 

 Carina represented only by a knob above. Face brown. Cheeks yellow; their greatest 

 width about one-fifth greatest diameter of eyes. 



Acrostichal hairs in six rows; no prescutellars. Mesonotum and scutellum dull reddish- 

 yellow. Legs yellow. 



Abdomen dark brown, each segment with an indistinct posterior darker band. 



Wings clouded along costa and veins, especially on cross-veins and near the wing tips. 

 Costal index about 2.4; fourth-vein index about 2.0; 5x index about 1.3; 4c index about 1.2. 



Length body 1.7 mm.; wing 1.8 mm. 



Specimen examined: Montego Bay, Jamaica. This specimen is in the 

 collection of C. W. Johnson, who identified it as D. sororia. I am in agree- 



