1916] North American Drosophilidce 325 



ChjTnomyza Czerny. 1903. Zts. Hymenopt. III. 



This genus has not hitherto been reported from North 

 America, but Drosophila amoena Lw. and D. procnemis Willist. 

 both belong here. The genus is easily separable from Drosophila 

 in that it has bare eyes; small postvertical bristles; second 

 orbital small or missing; a fourth orbital, below the third, large, 

 and reclinate; prominent male genitalia. The species are 

 usually rather slender, often with pigmented wings, and have 

 the habit of waving their wings. They are frequently found 

 around bleeding trees, but C. amcBna and C. procnemis will 

 breed on fermenting fruit. C. amoena is frequently collected 

 with the sweeping net, and is often very common around 

 tomatoes and windfall apples. It is also often seen on windows. 

 C. procnemis occurs from New York to Trinidad and Panama. 



C. caudatula Oldenberg, 1914, Arch. Naturgesch. LXXX, 

 A. Heft 2, 14, was described from Herkulesbad, in the southern 

 Carpathians. Prof. Melander lent me two specimens, collected 

 at Pullman and at Mt. Constitution, both in Washington. 

 I have carefully compared these specimens with Oldenberg' s 

 very full description, and can find no significant difference, 

 even in the external male genitalia. There is, so far as I am 

 aware, no other record of the species. 



The three species above, with the new one described below, 

 may be separated by the following key : 



1. Wings much spotted; front legs yellow C. amoena Loew. 



Wings clear, or blackish along anterior margin, or with a white tip; front 



femora, tibiae, and first tarsal joints blackish 2 



2. Front dark opaque brown 3 



Front yellow or reddish yellow C. procnemis Williston 



3. Wings clear; face whitish C. caudatula Oldenberg 



Costal cell brown; face brown C. aldrichii n. sp. 



Chymomyza aldrichii, n. sp. 



cf. Arista with four branches above and two below. Antennse 

 reddish brown. Front nearh' one-half width of head, wider above; 

 reddish brown, orbits and triangle darker. Second orbital reduced 

 to a minute hair, the other three approximately equal in size. Carina 

 very small and confined to upper part of face. Face brown, somewhat 

 concave. There is a row of bristles on the oral margin, the anterior 

 one being slightly longer than the others. Cheeks yellow. Eyes bare. 



Dorsum of thorax and scutellum shining dark reddish brown. 

 Pleuree brownish yellow. Coxae and legs pale yellow, except as follows; 

 fore femora and tibiae dark brown, fore tarsi and hind tibise brownish 

 veliow. 



