SYSTEMATIC ACCOUNT. 63 



M. pcecilogastra, M. dimidiata, M. thoracis, and M. graiiosa are all fre- 

 quenters of fungi, in which at least the last three breed. 



The four American species may be distinguished by the following key: 



1. Costal index little over 1.0; a black band from apex of costal cell to apex of anal 



cell M. projecians 



Costal index at least 1.3; no band at base of wrings 2 



2. Scutellum velvety M. dimidiata 



Scutellum shining 3 



3. Abdomen mostly black, yellow marks only on fifth segment M. pleuralis 



Abdomen black and yellow on each segment M. thoracis 



Mycodrosophila dimidiata Loew. 1862. Berl. ent. Zt., 6 (as Drosophila). 



Specimens examined : Franconia, New Hampshire (Mrs. Slosson) ; Woods 

 Hole, Massachusetts; Alpine, Riverton (C. W. Johnson), Fort Lee, New 

 Jersey; Pittsburgh, Pennsylvania (H. Kahl) ; District of Columbia; Plum- 

 mer's Island, Maryland (R. C. Shannon); North Carolina; Bloomington, 

 Indiana (F. Payne); Flat Rock (F. N. Duncan), type locality (Loew 

 material), Illinois; Georgia; Kushla, Alabama. 



M. pleuralis Williston. 1896. Trans. Ent. Soc. London, p. 411 (as Drosophila). 



Not seen. Described from St. Vincent, West Indies. 

 M. thoracis Williston. 1896. Trans. Ent. Soc. London, p. 411 (as Drosophila). 



Specimens examined: Isle of Pines (bred from fungi, C. W. Metz). 

 Described from St. Vincent, West Indies. 



M. projectans Sturtevant. 1916. Ann. Ent. Soc. Amer., 9, 342 (as Drosophila). 



Specimens examined: San Francisco Mountains, Haiti (A. Busck); 

 Montserrat, Trinidad, West Indies (A. Busck). 



Scaptomyza Hardy. 1849. Proc. Berwickshire Nat. Club, 349. 



Very close to Drosophila, but differs in the following respects: two or four acrostichal 

 rows of hairs in front of the transverse suture (six or more in Drosophila), two rows between 

 the dorsocentral bristles (four or more in Drosophila) ; occiput more convex than in Droso- 

 phila; thorax, abdomen, and wings more slender; prescutellars never present. 



The larvae are usually leaf-miners, but this is not invariably the case. 

 I have bred both S. adusta Loew and S. graminum Fallen on tomato fruit, 

 on potato tubers, and on banana agar, though these species are both ordi- 

 narily leaf-miners. Malloch has bred S. adusta from mulberry sap. 



This genus was based on the two European species Drosophila graminum 

 Fallen and D. flaveola Meigen. D. graminum was designated as the type 

 by Coquillett (1910, Proc. U. S. Nat. Mus., 37, 603). The following species 

 may be taken as valid members of the group : 

 Palsearctic: Scaptomyza amoma Meigen; S. flava Fallen; S. flaveola Meigen; S. gracilis 



Walker; S. graminum Fallen; S. griseola Zetterstedt; *S. incana Meigen; S. 



rufipes Meigen; S. tetrasticha Becker; S. unipunctum Zetterstedt (Czerny. 



1903, Wien. ent. Zeit., 22). 

 Nearctic: S. adusta Loew; S. graminum Fallen; S. terminalis Loew. 

 Neotropical: S. vittala Coquillett. 

 Oriental: S. bimaculata de Meijere; S. substrigosa de Meijere. 



These may be summarized thus: 



Palsearctic 10 



Nearctic 3 



Neotropical 1 



Oriental 2 



Total 16 



Less 1, for double entry of graminum 15 



