SYSTEMATIC ACCOUNT. 75 



Datura and melon flowers in Cuba, and in morning glories in Costa Rica and 

 Florida. Dr. Metz reports it common in cotton flowers in Jamaica. We 

 have reared adults from the decaying petals of such flowers, and in addition 

 Dr. Metz has bred the species on tomato fruit. 



The description of Drosophila mauiensis Grimshaw, from Hawaii, sug- 

 gests that that form is probably similar to this and to D. tristani. Its habits 

 are not recorded. 



The mating habits of D. luizii are recorded elsewhere in this paper. 



Drosophila tristani, new species. 



9 . Arista with five short branches above and three below. Antennae dark brown. 

 Front over one-third width of head, wider above; black. Second orbital about one-sixth 

 other two. Only one prominent oral bristle. Carina very broad and flat; face black. 

 Cheeks dark brown; their greatest width about one-fifth greatest diameter of eyes. Eyes 

 with short pile. 



Acrostichal hairs in eight rows; no prescutellar bristles. Mesonotum and scutellum 

 moderately shining black. Pleurae black. Coxae and femora dark brown, tibiae and tarsi 

 pale yellowish-brown. Apical and preapical bristles on first and second tibiae, preapicals on 

 third. 



Abdomen shining black. 



Wings clear. Costal index about 2.8; fourth-vein index about 1.8; 5x index about 1.3; 

 Ac index about 0.9. 



Length body 1.8 mm.; wing 2.0 mm. 



Type, San Jose, Costa Rica, March 1915, in the corolla of an Ipomea 

 flower. The species is named for Professor J. F. Tristan, who was acting 

 as my guide when the type and only specimen was collected. 



Drosophila alfari, new species. 



cf . Arista with about five branches above and two below. Antennae brown. Front 

 over one-third width of head, wider above; dark brown, lighter below. Second orbital 

 about one-fifth other two. Only one prominent oral bristle. Carina broad and flat; face 

 brown. Cheeks brown; their greatest width about one-fourth greatest diameter of eyes. 

 Eyes with short pile. 



Acrostichal hairs in eight rows; no prescutellars. Mesonotum and scutellum dark 

 brown, slightly shining. Pleurae dull brown. Legs pale yellow. Preapical bristles on all 

 tibiae, apicals discernible only on second pair. 



Two basal segments of abdomen dull brown; third to fiifth segments brownish yellow, 

 with posterior interrupted brown cross-bands. 



Wings clear, veins yellowish brown. Costal index about 3.6; fourth- vein index about 

 1.6; 5x index about 1.2; 4c index about 0.6. 



Length body 2.2 mm.; wing 2.3 mm. 



Type and 17 paratypes, San Jose, Costa Rica, March 1915, in the coroUse 

 of a large species of Datura, in which were also many specimens of D. florce. 

 The species is named for Dr. A. Alfaro, of the National Museum at San Jose. 



The females among the paratypes agree with the above description of 

 the male. There are some specimens, of both sexes, in the lot that have 

 some yellow on the two basal segments of the abdomen. 



Group E. 



Preapicals evident only on third tibiae; pleurae or mesonotum striped; carina narrow. 



Drosophila prognatha Sturtevant. 1916. Ann. Ent. Soc. America, 9, 340. 



&, 9. Arista with about six branches above and two below. Antennae yellow, third 

 joint very long and covered with yellow hairs. Front over one-third width of head; dull 

 yellow, ocellar dot brown. Second orbital one-fourth other two. Vibrissae long, other 

 oral bristles short. Proboscis prominent and projecting forward. Carina short, low, 

 narrow, and confined to upper part of face; face dull yellow. Cheeks yellow, a brown spot 

 on each side, just above and behind vibrissa. Greatest width of cheeks about one-sixth 

 greatest diameter of eyes. Eyes with yellow pile. 



