AKT. 4 NEW PARASITIC HYMENOPTEKA GAHAN 35 



those obtained from the relativ^ely large egg of C. maidis and the 

 smallest were bred from eggs of G. minima. Aside from this variation 

 in size, however, the series presents a surprisingly small amount of 

 deviation from type. There is some variation in the relative lengths 

 of the funicle joints and to a very slight extent in the proportions of 

 the wings; the median row of discal cilia in the apex of hind wing 

 may contain as many as six cilia or may be entirely absent; the 

 femora in some individuals lack almost entirely the dark brownish 

 infuscation; in other respects the series seems to be uniform. 



Seldom is a taxonomist privileged to study a series of specimens 

 such as this, and my thanks are due to Mr. Satterthwaite for the 

 opportunity. 



IDIOCENTRUS, new genus 



Probably most nearly related to Polynemoidea Girault and Stethy- 

 nium Enoch but differing from both in the extraordinary forward 

 extension of the venter of the abdomen beneath the thorax. The 

 nearest approach to this character known to the writer is found in the 

 genus Anaphoidea Girault in which the venter at base is somewhat 

 prolonged downward and forward but to a much less extent than in 

 the present genus. Anaphoidea may be readily separated from 

 Idiocentrus by the fact that the antennal club is 2-jointed instead 

 of 3-jointed, the antenna 10-jointed instead of 11-jointed, the abdo- 

 men much shorter and the ovipositor scarcely exserted beyond the tip 

 of abdomen. 



Female. — Long and slender. Abdomen much longer than the head 

 and thorax, completely sessile, with the ventral segments modified to 

 form a membranous pouch or sheath which extends forward beneath 

 the thorax and between the legs to reach the head, the ovipositor ex- 

 tending forward within this pouch to its anterior extremity and then 

 folding back and running posteriorly to the apex of abdomen where 

 it emerges, its sheath exserted about one-fifth the length of abdomen. 

 Antennae 11-jointed, the club indistinctly 3-jointed ; funicle joints all 

 rather long; thorax slender and distinctly longer than broad; prono- 

 tum rather large and conical anteriorly; parapsidal grooves present 

 and the mesoscutum with a fine median longitudinal groove; scutel- 

 lum somewhat longer than broad; axillae small and broadly sepa- 

 rated; metano turn short and transverse; propodeum about as long as 

 the scutellum and metanotum together, broad; legs long and slender; 

 front femora somewhat longer than either of the other pairs; hind 

 trochanters nearly as long as their coxae; front tibial spur distinctly 

 forked at apex; tarsi 4-jointed; forewings broad, marginal vein about 

 twice as long as stigmal, submarginal vein at the margin of wing, no 

 costal cell present; hind wings narrow. 



Tijpe of the genvs. — Idiocentrufi mirus, new species. 



