12 HYMEXOPTERA ACULEATA. 



double, /(!)/()()•, tilna, aud iars'i. On tlie front leg is a beautiful 

 arrangement for cleaning the antennae, &c., tlie spur or 

 c/ilcar at the apex of tlie tibia is modified so as to form a sort 

 of razor or knife-like organ, varying much in form, with 

 a sharp edge on its inner side, which fits against a semi- 

 circular emargination in the basal joint of the tarsi, set 

 with fine teeth like those of a comb. The antennse can be 

 passed between these organs and so cleaned. I have 

 frequently watched a wasp thus performing her toilet. The 

 hairs near the apex of the front tibiie are also frequently 

 modified, having knife-like edges, evidently also for cleans- 

 ing purposes. The tarsi are usually five-jointed, and are 

 occasionally much dilated and modified. The intermediate 

 legs have usually two calcaria at the apex of the tibise, and 

 in a few cases the femora near the base have a dense row of 

 spine-like hairs beneath ; the posterior legs are very sub- 

 ject to variability in form ; in the AnthophiJa they frequently 

 carry the pollen collecting apparatus, and their tibise are 

 usually more or less dilated and densely clothed with hairs; 

 in Bombus they are very smooth outwardly, with a series 

 of long curved hairs on each edge, which serve as a basket 

 to carry the polkn, and are also occasionally used to carry 

 mud or clay ; the sides of the tibiaj towards the abdomen 

 are densely clothed with short hairs with dilated apices 

 with sharp edges like spades, doubtless used for cleaning off 

 the pollen grains, &c. The posterior tibiis have usually two 

 calcaria, but in the genus Ajiis they have none. The tarsi 

 have the basal joint more or less dilated in the Ant/iophila ; 

 the uiignicnli are usually well developed and often toothed, 

 and the jmlviUns in some of the fossorial genera is very 

 large. Special male characteristics are of frequent occur- 

 rence in the legs of the Aculeata which do not occur in 

 their respective females. 



Abdomen — this is usually oval, but sometimes elongate, 

 and occasionally nearly round. There are usually seven 

 segments visible dorsally in the c?, and six in the ?, 

 ventrally there is usually one segment less visible, but the 



