SYSTEMATIC ACCOUNT. 79 



Abdomen shining black; three basal segments with anterior bands of reddish brown, 

 which do not reach the lateral margin. In some specimens (females) the abdomen is 

 reddish yellow, each segment with a posterior black band. 



Wings with small brownish clouds on each cross-vein. Costal index about 3.9; fourth- 

 vein index about 1.7; 5x index about 1.0; 4c index about 0.9. 



Length body 2.5 mm.; wing 2.5 mm. 



Specimens examined: Herradura (C. W. Metz), Havana (type material), 

 Santiago de las Vegas, Aguada Pasajeros, Cristo (C. W. Metz), Cuba; 

 Sanchez, Haiti (F. E. Watson); Mayaguez, Arecibo, Jayuya, Adjuntas, 

 Porto Rico (Lutz and Mutchler); Dominica (F, E. Lutz); San Jose, Port 

 Limon, Costa Rica; Panama, Republic of Panama; Lakeland (C. W. Metz), 

 Tampa (C. W. Metz), Orlando (J. M. Aldrich coll.), Fort Lauderdale (C. W. 

 Metz), Daytona (C. W. Johnson), Miami, Florida. 



This species is quite variable in color, but Dr. Metz and I have bred 

 several stocks in the laboratory, and have found these variations not to be 

 inherited, but to depend on the conditions under which the larvae develop. 

 Pale specimens of the females are very similar to D. similis Williston, and I 

 have been unable to devise any satisfactory method of separating them in 

 the case of pinned specimens. The two species are quite distinct, and we 

 have been unable to cross them. 



D. cardini is very common about fruit in the tropics. I have bred it 

 from banana and papaya. The development, from egg to adult, requires 

 about two weeks at summer temperature. 



The eggs have four filaments. The chromosomes have been described 

 by Metz (1916, Amer. Nat., 50, see p. 39 of this paper). The mating 

 habits are described on page 5. 



Drosophila similis Williston. 1896. Trans. Ent. See. London, 41S. (Not Lamb. 1914. 



Trans. Linn. Soc. London, 16, 347.) 



cf, 9. Arista with about six branches above and three below, .\ntennae yellow, 

 third joint darker. Front over one-third width of head, wider above; yeUow. Second 

 orbital one-fourth other two. Second oral bristle about three-fourths first. Carina broad, 

 flat; face yellow. Cheeks yellow; their greatest width about one-fifth greatest diameter 

 of eyes. Eyes pilose. 



Acrostichal hairs in six rows; no prescutellars. Mesonotum and scutellum brownish 

 yellow, sUghtly shining. Pleurae and legs pale yellow. Apical and preapical bristles on 

 first and second tibiae, preapicals on third. 



Abdomen yellow, each segment with a posterior blackish-brown band; the bands on 

 the third, fourth, and fifth segments interrupted in the mid-dorsal region. 



Wings slightly clouded on posterior cross- vein. Costal index about 3.2; fourth- vein 

 index about 1.7; 5x index about 1.2; 4c index about 0.8. 



Length body 2.0 mm.; wing 2.2 mm. 



Specimens examined: Herradura (C. W. Metz), Havana, Santiago de las 

 Vegas, Bartle (C. W. Metz), Cristo (C. W. Metz), Cuba; Porus, Port 

 Antonio, Jamaica (C. W. Metz); St. Vincent (Williston type material); 

 Bay Mansion, Barbados (H. A. Ballou). Specimens from Florida, Haiti, 

 Trinidad, Panama, Honduras, and the State of Vera Cruz in Mexico have 

 been examined that possibly belong here; but the lack of any really satis- 

 factory character to separate this species from pale specimens of D. cardini 

 Sturtevant makes all these latter determinations doubtful. 



Dr. Metz has studied this form in the laboratory, and has reported on 

 its chromosomes (see p. 39), and on a mutation that he obtained in it 

 (see p. 14). He has also seen the egg, which he states has four filaments. 



This species is not uncommon about fruit in Cuba. It has been bred on 

 banana through several generations in the laboratory without difficulty. 



