MONOGRAPH OF THE NORTH AMERICAN PROCTOTRYPID^. 103 



abdomen is quite distinct. The nou-lobed hind wings, venation, dif- 

 ferent anteuniie, and shape of mandibles, at once separate the species 

 in this group from the Bethylinai, Emboleminas, and the Dryinime; 

 while from the only two groups that follow, with which they would 

 likely be confused — the Scelioninre and the Platygasterinae, which 

 like themselves have non-lobed hind wings and the antennte inserted 

 close to the mouth — they may be readily distinguished by the widely 

 different antennae, the shajje of the head, venation, and non-carinated 

 abdomen. 



If we accept the published records as accurate, this group has great 

 diversity of habits. 



Ratzeburg has recorded Megaspilus sp. from a bombycid, a syrphid, 

 two cecidomyiids, a Chermes, a scolytid and a tortricid ; Ceraphron species 

 from a tineid, a Tomicus, a GurcuUo and a Brachonyx; and a Lygocerus 

 from a cynipid. Unquestionably, so far as the hosts are concerned, 

 some of these records are inaccurate. The records in this country and 

 others published abroad, show the group attacks almost exclusively 

 the homopterous f-dmily ApMdidw, and the dipterous family Cecidomyikke. 

 All reared by me, as well as those reared by Dr. Riley, except in a single 

 instance (the rearing of a Lygocerus, by Dr. Riley, from a tortricid, 

 Sarrothripa rawayana, which is of questionable accuracy) have been 

 from Aphids and Cecidomyiids. It is not improbable, therefore, that a 

 parasitized Aphid was on the same leaf when the Lepidopteron was 

 I)laced in the breeding jar. 



Some such explanation may also account for the rearing of these in- 

 sects by Ratzeburg from Lepidoptera, and his rearings from Coleoptera 

 may be accounted for by the supposition that they were accomi)anied 

 by inquilinous Dii)terous larvai. 



To accept without question such diversity of habits in the genera of 

 this group it seems to me would be unscientific. 



The group seems to divide naturally into two tribes distinguished 

 as follows : 

 Marginal vein stigniated; antennte, with the same number of joints in both sexes, 



11-joiuted Tribe I. — Megaspilini 



Marginal vein linear, never stigmated; antennae with a less number of joints in the 

 females than in the males; males with 10- or 11-jointed antennae; females 9- or 

 10-jointed Tribe II.— Cekaphronini 



Tribe I. — MEaASPiLiNi. 



The genera in this tribe are not numerous and may be tabulated as 

 follows : 



TABLE OF GENERA. 

 FKMAXES. 



1. Mesonotum without or with 1 or 2 imj)ressed lines 2 



Mesonotum with 3 impressed lines. 

 Metathorax with a forked spine at base Habropelte Thorns. 



