ART. 15. REVISION OF ICHNEUMON-FLIES MUESEBECK. 7 



Micro gastennae Cresson, Synopsis Hymen. N. Amer., 1887, pp. 55, 59. 

 Microgasteridae Marshall, in Andrg, Species Hymen. Europe, vol. 4, 1888, 



p. 439. 

 Microgasterinae Ashmead, Proc. Ent. Soc. Wash., vol. 4, 1898, p. 165. — 



Proc. U. S. Nat. Mus., vol. 23. 1900, p. 130.— Szepligeti, in Wytsman's 



Genera Insectorum, fasc. 22, 1904, p. 102. 

 Microgastcrides Lyle, The Entomologist, vol. 49, 191G, p. 122. 



Head transverse, the occiput usually immargined ; clypeus not 

 emarginate ; palpi never so short as in the Neoneurinae, ,and always 

 with more segments; antennae variable, but usually the number of 

 segments is constant for each genus; eyes usually hairy; thorax 

 stout ; parapsidal grooves usually wanting ; radius of fore wing want- 

 ing or abbreviated, never complete, the radial cell being always open 

 and never verj^ narrow; second cubital cell small, triangular, often 

 confluent with third cubital cell ; legs normal ; the spurs of the pos- 

 terior tibiae variable, very short to very long, but constant within 

 the species ; tarsal claws always distinct ; abdomen sessile ; ovipositor 

 varying from sub-exserted to longer than the abdomen. 



Most known species of Miei'ogasterinae are properly placed in this 

 subfamily without difficulty. However, species of the more or less 

 aberrant genera, Adelius, Mirax, Mesocoelus, and Oligoneurus, none 

 of which contains more than a few described forms, are sometimes 

 erroneously referred to other groups. The most dependable charac- 

 ters for distinguishing the Micro gasterinae are found in the wings — 

 the more or less abbreviated radius, the rather full radial cell, and 

 the small or wanting second cubital cell. These characters combined 

 with those noted above will suffice to distinguish between members 

 of this and allied groups. 



Foerster originally included eight genera in what he called the Mi- 

 crogasteroidae. Six of these, Adelius^ Dirrhope^ Mirax^ Apanteles, 

 Microplitis, and Microgaster, are still retained in the subfamily as 

 we limit it to-day. The other two genera, EccUtes and CardiocMles, 

 have been excluded because of the possession of a complete radial cell. 

 As indicated above, EccUtes may be long to the Blaclnae; Card'wchiles 

 at present constitutes a separate subfamily. 



Mesocoelus^ Mirax^ and Adelius contain very few species and none 

 of these species is well represented in any known collection. Apantehs, 

 MicropUtis, and Microgaster, which togetlier constitute the genus 

 Microgaster as understood by Latreille, are very well represented in 

 our fauna, and many of the species are exceedingly common and 

 generally well known. These three genera make up a single natural 

 group, differing markedly from the remaining genera of the sub- 

 family and clearly merging into one another. The only justification 

 for holding them distinct is the greater ease with which they can 

 thus be handled by the systematist. Including more than two hun- 

 dred described North American species, the group would be quite 



