322 MEMOIES OF THE CARNEGIE MUSEUM 



Metathoracic spiracles oblong, linear or subreniform. 



Abdomen oblong, at least 2^ times as long as wide, dorsal segments 3-6 snbequal ; flagellum 

 filiform, the joints of the funicle longer than thick Catolaccus Thomson. 



46. Postmarginal vein longer than the stigmal ■ 47 



Postmarginal vein shorter than the stigmal or no longer 49 



47. Antennae with two ring-joints 48 



Antennae with three ring-joints. 



Metathorax short with a median carina and lateral folds, the latter intersected by a transverse 

 carina which extends from the short median carina ; the spiracles large, oblong. 



Neocatolaccus Ashmead. 



48. Metathorax tvitli a distinct median carina, the lateral folds incomplete, the spiracles usually oval ; head 



large, broad, the vertex broad Diglochis Forster. 



Metathorax without a median carina, the lateral folds absent, the spiracles oval or ovate, not 

 large ; head transverse, not large, the temples flat Parapteromalus Ashmead. 



49. Antennae inserted on or near the middle of the face, or far above the clypeus 50 



Antennae inserted far below the middle of the face or just above the clypeus. 



Head large, broad, the temples broad, acute ; metathorax short, the lateral folds absent ; abdo- 

 men very short, rounded, depressed .Coelopisthia Forster. 



Head large, broad, but the temples rounded, not acute ; metathorax notvery short, the lateral 

 folds complete ; abdomen oblong-oval, depressed .Dibrachys Forster. 



50. Antennae subclavate, pubescent, the club much stouter than the funicle, the pedicel much longer than 



the first joint of the funicle Metapachia Westwood. 



Antennae filiform, pubescent or pilose, the pedicel much shorter than the first joint of the funicle ; 

 funicle joints 1-4 distinctly longer than thick Arthrolytus Thomson. 



Subfamily II. Merisin^e. 



The absence of the spiracular sulci, an important character, alone distinguishes 

 this tribe ; otherwise it closely resembles the subfamily Pteromalinx, its relationship 

 being quite close through the tribe Eutelini, with the gall-inhabiting species in the 

 tribe Merisini. 



I have recognized three tribes ; the first being parasites of Coleoptera, the second 

 of Diptera, while the third attack Rhynchota belonging to the homopterous fam- 

 ilies Aphididse, Alearodidx and Guccidx. 



TABLE OF TRIBES. 



1 . Metanotum without a trace of a median carina 2 



Metanotum with the median carina more or less distinct or at least indicated basally ; mesonotum with 



incomplete furrows Tribe I. Roptrocerini. 



2. Mesonotum with incomplete furrows Tribe II. Merisini. 



Mesonotum with complete furrows Tribe III. Isoplatini. 



Tribe I. Roptrocerini. 

 This tribe is distinguished by the metanotum, which always has a more or less 

 distinct median carina ; or at least it is never wholly absent as in the Merisini and 

 the Isoplatini. 



