ASHMEAD : CLASSIFICATION OF THE CHALCID FLIES 351 



the spelling of long-established genera is most annoying, confusing and difficult to 

 follow and I hold, with many other zoologists, that the only way to free ourselves 

 from these perplexities is to adhere strictly to the original spelling and to treat all 

 genera incorrectly formed as mere combinations of letters without special signifi- 

 cance. In no other way can we secure permanency in nomenclature. 



All the species falling in this subfamily are apparently parasitic only upon the 

 larvae of Lepidoptera, and more especially upon various families in the suborder 

 Heterocera, particularly those belonging to the families Bombycidx, Noctuidse, Geo- 

 metridx and Tortricidss. 



Four minor groups, or tribes, have been recognized, distinguished by the num- 

 ber and length of the hind tibial spurs. 



TABLE OF TRIBES. 



1. Hind tibiae with only one apical spur 2 



Hind tibiae with two apical spurs. 



Hind tibial spurs very long ; pronotum anteriorly acute Tribe I. Euplectrini. 



Hind tibial spurs normal, never very long; pronotum anteriorly rounded.. Tribe II. Ophelinini. 



2. Hind tibial spur normal, rarely very long Tribe III. Elachertini. 



Tribe I. Euplectrini. 



This tribe is easily separated from the others by the two very long apical spurs 

 of the hind tibise, the inner spur being very nearly as long as the basal joint of the 

 tarsi. 



Although parasitic upon lepidopterous larvae, like the other tribes, it differs 

 widely from the others, whose habits are known, in that the larvae are either ex- 

 ternal feeders, or on reaching maturity, gnaw their Avay out of their host and spin 

 small silk cocoons, like some of the Braconidse, within which they pupate and un- 

 dergo their final transformation. All of the others either pupate as naked pupae, 

 without a cocoon, within the body of their hosts, or emerge and attach themselves 

 to the under or upper side of a leaf, or else conceal themselves in some convenient 

 crevice or under loose bark. 



TABLE OF GENERA. 



1. Females 2 



Males 3 



2. Scape in both sexes normal, slender ; postmarginal vein distinctly longer than the stigmal vein. 



Euplectrus Westwood (type Pteromalus bicolor Swederus). 

 Scape in male abnormally enlarged, swollen ; postmarginal vein not longer than the stigmal. 



Pachyscaplia Howard (type P. insularis How.). 



3. Scape of antennae normal Euplectrus Westwood. 



Scape of antennae enormously enlarged Pachyscapha Howaid. 



