ICHNEUMONS. 35 



and the middle subraarginal cell of the fore wing five-angled. 

 In others the acnleus is curved upwards more or less, especially 

 so in the Ophionides species, which have the abdomen more 

 or less compressed ; in some it curves so very much that one 

 wonders how the insect could put it to its proper use, viz. to 

 perforate the skin of the larvae in order to deposit the egg or 

 eggs. Ovipositors are sometimes very slim, and appear quite 

 inadequate for the function they have to perform. Such is 

 not indeed the case, as I have found out by that best of all 

 tests — practical experience. I once caught a large, red and 

 black Cri/ptus, with an aculeus as long as its abdomen, and 

 was holding it in my fingers, when to my surprise it turned 

 the sting downwards at right angles to its body, and then 

 with a jerk of its body caused this little bristle-like appendage 

 to give me as sharp a sting as if it had been done by a 

 wasp. 



There is one genus concerning which information is much 

 wanted; that is the apterous little Cryptides, of the genus 

 Pezoinachus, which greatly resemble small ants, but the 

 antennae point out the difference at a glance : some of these 

 have been bred from spiders' nests. 1 bred P. zonatus from 

 a nest, which I found last spring, attached to the upper part 

 of a blade of grass : it looked like a small dab of mud on the 

 end of the blade. The larva of this PezomacJius did not 

 require all the eggs the nest contained for its sustenance, 

 and consequently many little spiders were afterwards hatched. 

 Of this genus there are about fifty species recorded as British ; 

 eight only are males, the rest being females. Few of these 

 species have the sexes associated, without doubt. Lepi- 

 dopterists might greatly assist in determining the sexes. 

 1 once found the cocoon of the whitethorn sawflv {Tri- 

 chiosoma iucorum) with the end cut oif in the usual way 

 by the fly, clearly showing that a sawfly had emerged from 

 it, but at the bottom were four cocoons containing living 

 larvae; two of these I killed accidentally, but the other two 

 produced ichneumons, Cri/p/us migrator. Of course I cannot 

 be certain that the eggs were laid in the larva of the savvflv, 

 and on becoming fidl-fed had issued from the larva, and 

 formed their cocoons inside of the cocoon of the sawfly, 

 having left sufficient life in the sawfly larva to enable it to go 

 through its transformations and to emerge a perfect insect ; 

 still such is the inference. Some ichneumons deposit only a 

 single egg in a larva, whilst others insert a quantity ; size 

 probably dictates the number to the ichneumon that she may 



