82 THE CANADIAN ENTOMOLOGIST. 



In these insects, as in the Uroceridse, the hinder-wing has upon its 

 anterior margin a row of minute hooks with which to hold the posterior 

 border of the front one. The number of the hooks is, however, much 

 less, there being only about a dozen scattered along the outer half of the 

 wing. 



Of our two species the larger and handsomer is R. atrata, of which 

 my specimens vary in length from a little over one and one-quarter inches 

 to nearly two. The head is a rich yellow, with the exception of the eyes 

 and a slight band, bearing the ocelli, on the vertex. The slender antennae, 

 about an inch long, are also yellow, as, likewise, are the extremely long 

 legs, with the exception of the upper joints of the posterior pairs. The 

 thorax and abdomen are black. The wings, which expand from two to 

 two and three-quarter inches, are transparent, but with a dark smoky 

 tinge. The female is furnished with an ovipositor from four to Jive and 

 one-half i?iches in length ; flattened and scarcely stouter than a hair. 



R. lunator is more common, at least in this vicinity, and varies much 

 more in size, the largest specimens being fully twice as big as the lesser 

 ones. The body varies in length from three-quarters of an inch to one 

 and one-half inches, and bears at its posterior extremity an ovipositor 

 projecting from one and one-half to three and three-quarter inches. 



The head is yellow with a dark band, in which are inserted the three 

 ocelli, between the eyes, parallel to which runs another dark line which 

 almost encircles the head. Lines also run from the base of the antennae 

 to the mandibles. The slender antennae are dark at the base but get 

 lighter toward the tip. The thorax and abdomen are dark brown, orna- 

 mented with lines and borders of yellow, which is also the color of the 

 legs. The wings (front pair) expand from one and one-quarter to two 

 and one-half inches, and have a quadrangular dark patch on the anterior 

 border. 



The larvae of both " long-stings " feed upon those of the Uroceridae 

 and other wood-borers, in which the female ichneumon deposits her eggs 

 by means of the long ovipositor. The method of performing this oper- 

 ation may often be witnessed during the summer by visiting beech trees 

 in which Tremex larvae are at work, but it is difficult to describe clearly 

 its accomplishment and the different postures of the insect during the 

 progress of her laborious and dangerous duty. A series of good drawings 

 (vould best convey a correct idea of the process, but I do not know of any 

 book in which such are to be found, while some illustrations are very 

 inaccurate. For instance, I saw the other day in a text book of zoology 



