90 GENERA OF HYMEXOPTERA. 



combined, slender, cylindrical at base, gradually Avidened towards the 

 apex, the second and following segments becoming gradually shorter 

 to apex. 



The females are common where they occur, wliilc the males are 

 exceetlingly rare. Their habits are unknown, Imt are doubtless 

 ])ai'asitic. 



TUBULIFERA. 



Tills grouj) of insects contains the single family Chrysididtc, char- 

 acterized by the abdomen having apparently very few segments, 

 from three to five, the remainder being modified into a telescopic and 

 retractile tube, which is drawn within the body when not required 

 for its legitimate purpose ; it is furnished at the extremity in the 

 males with the organs of generation and in the females with a minute 

 sting-like ovipositor. 



These insects, although of moderate size, are among the most 

 beautiful of our hymenojitera, being adorned with brilliant metallic 

 blue, green and ruby. The body is often dee])ly puncuiivd, the ab- 

 domen in some genera being almost rounded or semicircular and 

 entire at aj^ex, while in other genera, e. g. Chrysis, it is usually ter- 

 minated by a series of teeth, varying in number from two to six, the 

 apical margin being ])receded by a transverse row of deeji pits. 



In their economy the Chrysididte are said to difter from the pre- 

 ceding tribe in that the females do not deposit their eggs in the bodies 

 of other insects, but cuckoo-like, place them in the already provis- 

 ioned nests of other hymeno[)tera, chiefly those of solitary wasps and 

 bees, and being first hatched, these larvae feed upon and devour the 

 supply of food stored up for the support of the others, which ari' 

 thus starved and destroyed. 



Family CHRYSIDIDiE. 



The following synoptic table is coiupikil from an excellent mojio- 

 grapii of the family by Mr. S. F. Aaron, published in the Tith vol- 

 ume of these Transactions and illustialcd l)y sivcral plate- of well 

 drawn figures, leaving the compiler liiile oi- miihing to do but to 

 copy the characters given of the subfamilies and genera. 



The familv is divisible into four subfamilies, as follows: 



