1916] North American DrosophilidcB 331 



Wings clear, veins brown. Costal index about 3.0, 4th vein index 

 about 1.8, 5x index about 1.2, 4c index about 0.9. 



Length body 23^mm., wings 3mm. 



Type, allotype and genotypes from New York, N. Y. 

 The type and allotype were bred from a pineapple exposed at 

 Columbia University; they and their descendants are the only 

 specimens of the species that I have seen. The females agree 

 with the above description. 



This is the "species B" of Metz (1914 Journ. Exper. Zool. 

 17, p. 50; 1915. Am. Nat. 49, p. 187). It is a fruit eating form, 

 and has been kept in the laboratory more than two years, 

 banana being used for food. 



The species resembles D. robusta n. sp. and D. melanica n. sp. 

 rather closely. The six acrostichal rows will separate it from 

 most specimens of D. robusta; and from both these species it 

 may be distinguished by its broad cheeks and relatively long 

 second oral bristle. 



Drosophila robusta, n. sp. 



cT. Arista with six branches above and three below. Antennae 

 dark brown, second joint pollinose distally. Front over one-third 

 width of head; dark coffee brown, orbits and triangle slightly grayish 

 pollinose. Second orbital fine, about one-fourth length of other two. 

 Second oral bristle not quite one-half size of vibrissa. More than one 

 prominent bristle on each palpus. Carina broad, very sHghtly sulcate. 

 Face somewhat shining, brown. Cheeks brown, their greatest width 

 scarcely one-sixth greatest diameter of eyes. Eyes with short black 



pile. . . 



Acrostichal hairs somewhat irregular, m six to eight rows; no 

 prescutellar bristles. Dorsum of thorax dark dull brown, with four 

 faint pollinose longitudinal stripes. Scutellum and pleurae dark dull 

 brown. Legs pale brown; fore coxae blackish brown beneath, with a 

 whitish pollinose spot between them. Apical and preapical bristles 

 on first and second tibiae, preapicals on third. 



Abdomen grayish brown, each segment with a very broad dark 

 brown fascia on each side; these fasciae often nearly or quite meet 

 in the middorsal line. 



Wings clear; veins brown, subterminal part of first vein very dark. 

 Costal index about 4.0, 4th vein index about 1.0, 5x index about 1.2, 

 4c index about 0.7. 



Length body 2^mm., wings 2^imm. 



Type, allotype and numerous gonotypes, bred in New York, 

 N. Y., from stock obtained at Kushla, Alabama. I have 

 examined specimens of this species from Woods Hole, Mass., 



