G K( )M YZ IDvE— ( )SCINIDiE. 105 



This group, as here defined, inehides the Geomyzida' and 

 Opomyzida3 and a part of tlie Heteroneuridje of Loew. Tlie 

 insects included in it are always small, and sometimes minute. 

 The larva? of those feAV species of which the habits are known, 

 live in the stems of various plants. The flies are almost al- 

 ways caught with tlie heating net. 



TABLE OF GENKKA. 



1. Oral vihrissffi present. ......... 2 



()ral vilirissse wanting op indistinctly (lii'tcTcntiatcd from liairs. . 7 



2. Winus with bristles along the costa ; l)riistles of antenna; plumose; sec- 



ond basal cell confluent with the discal cell. 



CuRTONOTiiM* Macquart. 

 Flies not having the above characters. ...... -j 



;]. Costal Vein continuous about the wings; wings with nuirkings; posterior 



cross-vein very ol)lique ; arista pubesceiU. IIkteuociiroa Schiner. 



Flies not having the above characters. ...... 4 



4. Mesonotum bristly in the middle on tlu> jiosterior part onh'. . 5 

 Mesonotum ])ristly in the middle on the front; arista pectinate on the 



upper side. Ealiopteka Loew. 



5. Under side of the front femora with bristle-like spines or strong bristles ; 



arista pubescent. .......... 



Front femora without such bristles; front with one ])roclinate and one 

 divaricate bristle on each side. . . . Diastata Meigen. 



(). Second longituilinal vein flexuous. . . . Isciinomyia Loew. 



Second longitudinal vein not flexiious. . . Antiiomyza Fallen. 



7. Occiput llattened ; wings spotted Opomyza Fallen. 



Occiput convex ; wings not spotted. . Scvpiiklla K. Desvoidy. 



36. OSCINID^. 



Small, hare species. Head liemisph.erical, face usually ver- 

 tical in prolile ; oral border usually without vibrissas; front 

 broad, fiat, sometimes witli bristles at the vertex. Antenna' 

 usually short; third joint usually rounded. Abdomen ovate 

 or elli])tical; genitalia liidden. Wings moderately or very 



* This genus belongs more propi'rly with the Drosophilidae. 



i;} 



