ASHMEAD : CLASSIFICATION OF THE CHALCID FLIES 347 



Tribe II. Pteroptricini. 



This tribe is separated from the former by having 4-jointed tarsi, not five. It 

 forms a transition, or a connecting link, between the subfamihes Aphelininx and the 

 Tetrastechinx, some of its members are easily mistaken for some of those of the 

 latter. 



The very short, or nearly obsolete, stigmal vein, and the absence of the meso- 

 sternal furrow, will, however, readily distinguish them. 



The species attack principally the mealy-winged plant-lice, family Aleurodidse. 



TABLE OF GENERA. 



1. Females 2 



Males 3 



2. Antennae 8 jointed, normal, the last joint very short. Pteroptrix Westwood (type P. dimidiata Westw.). 

 Antennse 5-jointed, with 2 minute ring-joints, the last joint, or the club, greatly lengthened. 



Eretmocera Haldeman (type E. corni Haldeman.). 



3. Antennse 8-jointed Pteroptrix Westwood. 



Antennae 3-jointed (or 4-jointed with a ring-joint), the last joint very long. Eretmocera Haldeman. 



Subfamily III. Tetrastichin^. 

 1856. Tetrastichoidse, Familie 21, Forster, Hym. Stud., II., pp. 26 and 83. 

 1878. Tetrastichina, Tribus, Thomson, Hym. Skand., V., p. 180. 

 1886. Tetrastichin^e, Subfamily, Howard, Ent. Amer., I., p. 199 ; II., p. 98. 

 1897. Tetrastichinse, Subfamily III., Ashmead, Proc. Ent. Soc. Washington, IV., 

 p. 249. 

 This subfamily is closely allied to the Aphelininse, and some of the smaller 

 species falling in it, are easily confused with many in the Aphelinini, if attention is 

 not given to the difference in the length of the stigmal vein. 



table of tribes. 



Abdomen distinctly petiolate ; hind wings with a long, clavate marginal vein Tribe I. Ceratoneurini. 



Abdomen sessile or subsessile ; hind wings with a slender marginal vein Tribe II. Tetrasticbini. 



Tribe I. Ceratoneurini. 

 The distinctly petiolate abdomen, and the long clavate marginal vein in the hind 

 wings, found in no other tribe, will distinguish the tribe at a glance. 

 Only one genus is known : 



Antennae 10-jointed, Avith two ring-joints ; face with striae converging towards the mouth. 



Ceratoneura Ashmead (type C. petiolata Ashm.). 



Tribe II. Tetrastichini. 

 The sessile or subsessile abdomen, and the difference in the venation of the hind 

 wings separate this tribe from the Ceratoneurini. The scutellum has usually /our 



