368 Bit VySE AND COMB OF THE HYMENOPTERA. 



brush-like form in either species of the hjniienoptera. In the honey bee it 

 appears to have no especial fringe of bristles, but is membranous, thin, of 

 irregular outline, and doubled, like a leaf with the edges curled towards 

 each other, having the concave side opposed to the leg. The stout spines 

 iibove and below the notch, are a few of the usual spines w^hich abound on 

 this part of the leg. The teeth of the comb are seen in a regular curve, 

 fringing the inner contour of the notch, and pointing towards the centre 

 of the opening. 



The brush on the fore leg of a winged red ant well deserves the name. 

 Its back, or convex side, is armed towards the tip with finely pointed pro- 

 jections; and its concave side, from the tip to a large pointed process in the 

 neighborhood of the base, or for about two-thirds of its length, is fringed 

 with long, closely set teeth, which must render the brush an admirable 

 duster. There is no deep notch in the tarsus, as with the honey bee, but 

 a decided curve, wnth a gently sweeping and extended comb. 



The brush on the fore leg of the blue mud wasp (Pelopceus coeruleus) is 

 large, prominent, and of strikingly graceful form, as might be expected 

 from the characteristics of this sjDecies. The teeth of the brushing edge, 

 opposed to the leg, begin quite near the base, and extend downwards in a 

 prominent reversed curve to a large, pointed process, and are then suc- 

 ceeded by a close row of sharp spines to the tip. The teeth of the comb 

 are set in a notch, in the upper part of the tarsus, very much like that of 

 the honey bee, only not cut in with such a deep, short cu.rve. 



The white-horned horn-tail (Urocerus albicornis) is one of the largest of 

 the hymenoptera. It has long, narrow wings, and a long, cylindrical bod3^ 

 giving it somewhat the appearance of a dragon-fly; but it is much more 

 sluggish in its movements than the latter insect. The female is armed 

 with a long, slender borer, hinged to the middle of the under side of the 

 abdomen, with which she bores the trunk of the pine tree to deposit her 

 eggs. In this insect the brush and comb would hardl}^ be recognized, as 

 they have been strangel}- transformed into what may be called a thumb 

 and knives. The thumb is hinged to the lower end of the tibia, in the 

 usual position of the brush. It is nearly straight, fleshy, cylindrical and 

 -ends in a slightly curved spinous tip. Instead of the comb, found on most 

 other members of the great family of the hymenoptera, there is a long row 

 of curious appendages, gradually increasing in size as i\\Qj extend down- 

 wards, and set on the inner side of the enormously lengthened first tarsal 

 joint. They rise from a somewhat bulbous base, continue for about one- 

 third of their length with a cylindrical trunk, and then suddenly expand 

 in an extremely thin and transparent blade. 



They would evidently have formed a good model for the flint knives 

 made by our progenitors of the "stone age.". The back of each knife is 

 directed downwards; while the cutting edge, taking a broad sweep from 

 the handle to the extreme point, is directed upwards towards the thumb. 

 In the individuals w^hich I have examined, the thin upper edge of many of 



