104 DIPTERA OF NORTH AMERICA. 



Synopsis of the North American genera. 



.. f The third joint of the antennae not circular. 2 



1 The third joint of the antennae circular. Sciomyza Fall, 



f Antennae only a little prolonged ; front not excavated ; eyes not pro- 

 I tuherant. Tetanocera Bum. 



1 Antennae much prolonged ; front excavated ; eyes protuberant. 



Sepedon Latr. 



Gen. I. SCIOMYZA Fall. 



Only three N. A. specie? of this genus have been described, all 

 by Mr. Walker. His description of Sciom. antica is made in so 

 careless a manner that it is quite impossible to recognize it, and 

 Sciom. parallela Walk, seems to be no Sciomyza at all. Sciomyza 

 nigripalpa Walk, is certainly not among the three species known 

 to me. The scantiness of my present material scarcely warrants 

 my undertaking to describe the N. A. species of Sciomyza, but I 

 will present what I have to say about them, in connection with the 

 Sciomyzidse generally. 



There is no reason for discussing here the smaller genera sepa- 

 rated from the old genus Sciomyza, or to point out the subdivi- 

 sions to be made, since the three species known to me belong all 

 to the group of the typical species of Sciomyza. 



Synopsis of the Species.* 



, f Wings spotted. 1 nana Fall. 



I Wings not spotted, the transverse veins only clouded with brown. 2 

 „ S The two bristles on each side of the front extant. 2 obtusa Fall. 



I The foremost of the lateral frontal bristles wanting. 3 pubera, n. sp. 



1. S. liana Fall. ^ and J. — Cinerea, thorace vittato, alis nigro-macu- 

 latis. 



Gray, with the thorax striped, and the wings spotted with blackish. Long, 

 corp. 0.1—0.13. Long. al. 0.11—0.14. 



Syn. Sciomyza nana Fallen, Sciom. 15,12. — Meigen, Syst. Beschr. VI, 18, 

 19.— Zetterstedt, Dipt. Scand. V, 2109, IS. 



Quite agreeing with the European specimens. Ashy gray. 

 Front opaque yellow, with the ocellar triangle and the lateral 



* The fourth species, added when the manuscript was already in press, 

 is not included in this synopsis. — O. S. 



