Morphology of the Legs of Hymenopterous Insects, 195 
exactly like that of the honey-bee, except the part which I have 
termed the blade, in the modified tibial spur has its back more 
extended, and the whole back of the blade and the extended point 
thickly set with short spines, reminding one of the serrations on 
the antenne of many beetles like the Buprestids. In the car- 
penter-bees—X ylocopa—there is no variation from the type of 
the Bombus except the serrated margin of the blade is still more 
marked. In the female of the tailor-bees—Megachile—the ex- 
tended point and serrations are both absent, and we have again the 
form of this organ in the honey-bee. The number of the teeth in 
the cavity however, is less, there being from forty-five to fifty. In 
Osmia and Andrena (Fig. 3), the arrangement is much as in the 
Xylocopa; in Nomada the serrations 
are less spinous and more scattered, 
while in the beautiful species of Ango- 
chlora the cavity is quite shallow, the 
blade of the spur narrow, and the 
spines on the back and point of the 
blade slim and hair like. , Fio. 3. 
In the several families of wasps we find this pollen cleaner, well 
developed, and in some cases quite modified from the same in bees. 
In the paper-making wasps— Vespidee—it is much as in the lowest 
bees—N omada and Angochlora. The cavity is more shallow than 
in the honey-bee, the membranous portion of the blade is quite 
narrow, and the appendages on the point of the blade are hair-like, 
though those near the base remind one of saw teeth. 
In sand-wasps—Bembecidee—this organ is much as seen in bees 
and paper-making wasps; though the point of the blade is very 
long, and the back and point both thickly set with fine hairs. 
ioe In all species of mud wasps, belonging to 
se the family Sphegide (Fig 4) we find an in- 
teresting modification in the spur. Here the 
membranous portion of the blade is nearly 
Fra. 4, obsolete, while its inner margin is concave 
and fringed with a toothed brush much as seen in the cavity, 
though the teeth are shorter. The end of the blade is blunt, and 
ts from five to eight heavy appendages, which, when magni- 
fied, look like so many fingers. 
