THE CANADIAN ENTOMOLOGIST. 97 



powerful flight than if they moved separately. The junction is effected 

 by means of a number of minute hooks on the front edge of the wing, 

 which grasp the nervure or vein on the edge of the fore wing. These 

 hooks can be easily seen with a microscope of even low power, and form 

 a very interesting object. On a wing of Urocerus albicornis which I have 

 just examined there are thirty-eight of these hooks, giving the edge of the 

 wing the appearance, on a very small scale, of one of those horse-rakes 

 with curved teeth. De Geer informs us that he counted " more than forty 

 upon each hinder wing of a large ichneumon of the first class. Their 

 extremity is not pointed, it is rounded and as large as all the rest. They 

 are implanted in the nervure by which the wing is bordered/' and he adds : 

 '* I do not recall that M. de Reaumur nor any other author has made men- 

 tion of this property of the wings." He then proceeds to describe some 

 remarkable ichneumons of which the places of birth were unknown, 

 beginning with a " grand ichneumon of which the abdomen, ending in a 

 pointed tail, is not held to the thorax by a thread ; of which the thorax is 

 black, the body half black and half yellow, and the antennae and legs 

 yellow." Of this insect — Sirex gigas — already mentioned by Reaumur, a 

 detailed account is given, both of the male and female. It is styled 

 peculiar to the northern countries, and one of the largest, if not the largest 

 species found in Europe. It is to be seen flying in full day, noisily hum- 

 ming like the hornets and bees, and agitating continually its wings and 

 antennge like all ichneumons, of which this last feature is characteristic. 

 " I do not know their grubs, nor the place where they live, but the long 

 augur of the female is enough to show that they should lay their eggs in 

 other bodies, like other ichneumons. // would be curious to know all their 

 history. Linnaeus is mistaken in placing them in the family of the Saw- 

 flies (TenthrediuesJ." Yet these insects, whether we consider the shape 

 of their bodies, the formation of the female appendages, or the shape and 

 habits of their grubs, appear much less removed from the Saw-flies than 

 the ichneumons, or in other words, to occupy an intermediate place 

 -between these groups. We know that in the Saw-flies the females are 

 provided with a complex instrument for cutting slits in which to deposit 

 their eggs. This instrument consists of six- parts, two of which form a 

 sheath for the rest. Of these, two resemble very fine blades, notched on 

 the edge like a saw, and strengthened when in use by the remaining two 

 acting as backs. The saws, when not employed, are enclosed in the 

 sheath and received in a groove on the under side of the abdomen, so as 



