SYSTEMATIC ACCOUNT. 55 



present; mesopleurae bare; auxiliary vein rudimentary; costa reaches fourth vein, but is 

 very weak beyond the third; discal and second basal cells confluent; anal cell and anal 

 vein present. 



The genus was based on the European G. distigma Meigen. G. pruinosus 

 Bigot, from Tunis, is the only other Palsearctic species. The genus Gitonides, 

 which does not seem to me to be distinct, includes only the species G. 

 perspicax Knab, from Hawaii, the Philippines, and India. The data suggest 

 that it may have been introduced into Hawaii. These three are the only 

 species of the group now known. 



G. distigma breeds in the flower-heads of composites, and the larvse are 

 suspected of being aphidophagous. G. perspicax has been bred from larvse 

 feeding on mealy-bugs (Pseudococcus). 



I have seen the types of G. perspicax, and have examined European 

 material of G. distigma, identified by Bezzi and by Kertesz. 



Pseudiastata Coquillett. 1908. Proc. Ent. See. Wash., 9, 148. 



Arista minutely pubescent; three orbitals, anterior one convergent, posterior one nearer 

 to verticals than to middle orbital; front covered with small black hairs, as in Pseudo- 

 phortica; vibrissa large; carina very small; eyes bare; two dorsocentrals; prescutellars 

 present; preapicals on first tibiae, several bristles near the apices of second and third tibiae, 

 as in Pseudophortica; auxiUary vein rudimentary, but continued as a shadow to costa; 

 costa twice broken, with a large bristle just before the distal break and two such bristles 

 just before the proximal one; costa reaches fourth vein; discal and second basal cells 

 confluent. 



There is a single species, P. nehulosa Coquillett. It bears considerable 

 superficial resemblance to the genus Sapromyza, and it was first described 

 as a geomyzine. Examination shows many points of resemblance to the 

 genus Pseudophortica, from which it is easily distinguished by its arista. 

 Only one specimen has been recorded, that was taken at Plummer's Island, 

 Maryland, by H. S. Barber. Mr. Barber tells me that it was taken at night, 

 at a light. I have examined this specimen, and a second one that agrees 

 with it in all essential points, taken at Alajuelo, Panama, by A. Busck. 



Idiomyia Grimshaw. 1901. Fauna Haw., 3, 50. 



This genus is unique in the possession of an extra cross- vein, between the third and 

 fourth veins, near the posterior cross-vein. It is described as having the following char- 

 acters: auxiliary vein rudimentary; anal cell present; discal and second basal cells con- 

 fluent; eyes pubescent; arista plumose; three orbitals, disposed as usual; two pairs of 

 dorsocfentrals; two pairs of scutellars, posterior ones crossed; eyes oblique. Mr. Lamb 

 writes me that the vibrissa is absent. 



Six species are described in ''Fauna Hawaiiensis," all from the Hawaiian 

 Islands. The type is /. perkinsi Grimshaw. The species occur on four of 

 the larger islands of the group. 



Zygothrica Wiedemann. 1830. Achias Dipt. Genus, 16, 3. 



Drosophilura Hendel. 1913. Ent. Mitt., 2, 387. 



1 Sphyrnoceps de Meijere. 1915. Tijds. Ent., 58, suppl.; 58. 



Arista plumose; two or three orbitals; vibrissae present; ocellars present; postverticals 

 large; face protuberant; carina large; head broader than thorax; antenna inserted opposite 

 middle of eye; proboscis longer than height of head ; no prescutellars ; preapicals evident on 

 second and ttiird tibiae; discal and second basal cells confluent; costa twice broken, reaches 

 apex of fourth vein. 



The type species is Achias dispar Wiedemann, described from Brazil and 

 since recorded from Peru, Bolivia, and Panama. Z. aldrichii Sturtevant, 

 from Panama, is the only other American species. Sphijrnoceps brunneus 

 de Meijere, from the East Indies, probably also belongs here. I have 

 discussed the synonymy of these forms elsewhere (Sturtevant, 1920, Proc. 

 U. S. Nat. Mus. 58, 155). 



