86 THE NORTH AMERICAN SPECIES OF DROSOPHILA. 



are very favorable places to collect it, and it is almost certain to appear 

 about animal matter that has been preserved in formalin and then allowed 

 to become somewhat stale. It will breed freely in such material. It will 

 breed in fleshy fungi, but is rarely found about them in the woods. It is, 

 in fact, seldom to be found in the woods at all, though quite common about 

 houses, barns, or grocerj^ stores. 



Oviposition begins when the females are about three days old, and the 

 adults emerge about two weeks after the eggs are laid, at ordinary moderate 

 summer temperatures. The species is very easily kept in the laboratory, 

 and produces many offspring when kept on banana agar. If it is allowed 

 to breed in a culture for several weeks the agar becomes liquefied, which 

 it does not do in the case of D. melanogaster. 



Drosophila ordinaria Coqiiillett. 1904. Proc. Ent. Soc. Wash., 6, 190. 



9 . Arista with about six branches above and two below. Head bright yellow, dark- 

 brown ocellar spot. P'ront over one-third width of head, wider above. Second orbital 

 scarcely one-hali other two. Only one prominent oral bristle. Carina flat, not sulcate- 

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



Acrostichal hairs in six rows. Mesonotum, scutellum, pleurae, and legs yellow. Apical 

 and preapical bristles on first and second tibise, preapicals on third. 



Abdomen yellow, with an interrupted dark-brown posterior band on each segment. 



Wings clear. Costal index about 2.7; fourth- vein index about 1.4; 5x index about 1.2; 

 4c index about 0.8. 



Length body 2.8 mm.; wing 2.8 mm. 



Specimens examined: St. John's County, Quebec (C. W. Johnson coll.); 

 White Mountains, New Hampshire (Morrison, type material); Chester, 

 Massachusetts (C. W. Johnson). The species is recorded from New Jersey 

 in Smith's catalogue, but this is probably an error. All New Jersey speci- 

 mens so labeled that I have seen are D. transversa Fallen or D. putrida 

 Sturtevant. 



Nothing is known about the habits of this species. I have never seen it 

 alive. The male is unknown. 



Drosophila torrei, new species. 



9. Arista short, with four branches above and two below. Antennse pale yellow. 

 Front about one-third width of head; yellowish brown, ocellar dot dark brown. Second 

 orbital about one-half first. Second oral less than one-half first. Carina narrow; face 

 yellow. Cheeks yellow; their greatest width about one-fifth greatest diameter of eyes. 

 Ej'es with fine pile. 



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

 yellow. Legs and pleurae pale yellow. All thoracic hairs and bristles are yellowish brown. 

 Apical and preapical bristles on first and second tibitfi, preapicals on third. 



Abdomen yellow. 



Wings clear, veins yellow. Costal index about 2.0; fourth-vein index about 1.4; 5x 

 index about 1.0; 4c index about 1.0. 



Length body 2 mm.; wing 2 mm. 



Type, Havana, Cuba, January-February 1915. This specimen and three 

 gonotypes bred from her (1 male, 2 females) are the only specimens seen. 

 The male agrees with the above description. These specimens were reared 

 on pineapple. 



This species is named for Dr. Carlos de la Torre, whose hospitality at the 

 National tjniversity in Havana the author was enjoying when the type was 

 collected. 

 Drosophila duncani Sttirtevant. 1918. Bull. Amer. Mus. Nat. Hist., 38, 446. 



Arista with about six branches above and two below. Antennse yellow, third joint _ 

 darker, long, and clothed with long yellow hairs. Front over one-third width of head, ' 



