OF WASHINGTON, VOLUME XVI, 1914 179 



NOTES ON THE DIPTEROUS GENUS CHYROMYA R-D. 



BY J. R. MALLOCH, Urbana, III. 



This genus has undergone several nomenclatorial changes since 

 1830 as indicated by the synonymy given below. 



Chyromya R-D., Essai My ode., p. 621 (1830). 



Pelithophila of authors, not Hagenbach, Symbol. Faun, insect. Helv., 



p. 48, (1822). 



Lisella R-D., Essai Myod., p. 649 (1830). 

 Sapromyza part Fallen, Zetterstedt and Meigen. 

 Scyphella'R-D., Essai Myod., p. 050 (1830). 

 Thyrimyza Zetterstedt, Dipt. Scand., vol. 6, p. 2336 (1847). 



In addition to these we have the misspelled names Chrymomyia 

 and Peletophila by Becker 1 and the emendation to Chiromyia by 

 Alt-lander 2 following Scudder. 3 



The name Pelethophila cannot be used as the only species orig- 

 inally included in the genus is a true Psila ( fimataria Linne). 



The position also of the genus has been subject to some changes. 

 The older authors placed it in Sapromyzidae while some recent 

 authors have placed it in Opomyzidae. The latest arrangement 

 regulates it to Opomyzinffi a subfamily of Geomyzidae. 



The generic characters are as follows: Post-vertical bristles 

 convergent; ocellar bristles divergent; ocellar triangle and orbits 

 poorly denned; usually 3 pairs of orbital bristles, the anterior 

 pair convergent; antennae small, the third joint not elongated, 

 apically rounded, arista almost bare; face slightly receding; 

 cheeks about half as high as eye, vibrissse weak; proboscis fleshy; 

 palpi normal. Thorax with 2-4 pairs of dorso-central bristles 

 and distinct and rather numerous discal setulse; mesopleura 

 with usually 2 bristles; sterno-pleura with 1 bristle. Legs with- 

 out preapical bristle. Wings with costa twice broken; auxilary 

 vein indistinct, incomplete, or joining costa; costa unspined; 

 discal cell elongate; outer cross vein beyond middle of wing; 

 an.nl cell complete; anal vein reaching almost or quite to margin. 



Synopsis of North American Species of Ghyromya. 



1. Fore and hind femora of male much swollen; large species, 3-3.5 mm. 



femorella 

 Fore and hind femora of male not swollen 2 



2. Thorax with 4 pairs of dorso-central bristles 3 



Thorax with 2-3 pairs of dorso-central bristles 4 



^eitschr. fur Syst. Hymen, u. Dipt., vl. 4, 1904, p. 129. 



2 Jour. N. Y. Ent. Soc., vol. 21, p. 300 (1913). 



3 Nomen. Zool. 



