160 BRITISH APHIDES. 



empty cells as are excavated in brambles or rotten 

 posts. 



The family Crabroniclee is rich in the number of 

 species. The winged forms may be generally recog- 

 nised by their wasp-like characters, and the bright 

 yellow and brown colouring of their bodies. 



For the principal generic characters Professor West- 

 wood's ' Introduction,' vol. ii, p. 191, may be advanta- 

 geously consulted, but in this slight sketch the head of 

 the CrabronidaB may be described as large and square ; 

 the antennse often thickened at their tips, the abdomen 

 more or less oval, and broadest in the middle, some- 

 times united to the thorax by a pedicle. The number 

 of the submarginal cells in the anterior wings varies 

 from one to four. The legs are moderate in length ; 

 the anterior tibise have a dilated spur, which is pecti- 

 nated on the inside. The basal joint of the fore tarsi 

 has a corresponding ciliated notch. 



J. Curtis relates that Mr. Waring, towards the end 

 of August, took him to a summer-house in his garden, 

 and then showed him multitudes of small black Hyme- 

 noptera entering the straws of the thatch, many of them 

 carrying Aphides in their mouths. These Hymeno- 

 ptera belonged to at least four different genera, amongst 

 which Curtis identified Hykeus annularis, Psen ater, 

 Pemphredon unicolcr, and a Diodontus* 



On splitting these straws he found in some masses of 

 pollen, and in others stores of numerous living Aphides. 



In 1837, Shuckard published his essay on the ' Fos- 

 sorial llymenoptera,' confirming Curtis' observations, 

 and adding new species to the then known list of 

 Aphidivorous Crabronidte.t 



In the following year A. Kennedy contributed an 

 important paper to the 'Philosophical Magazine,' which 

 contained much new matter and more complete infor- 

 mation on the same subject. | But, perhaps the best 



* Vide Curtis, ' Brit. Entom.,' 2nd edit., plates 496, 632, 652, &c. 



t W.E. Shuckard, 'Essay on the Indigenous Fossorial Hymenoptera.' 



X A. Kennedy, " Observ. on Hymenop.," ' Phil. Mag.,' vol. xii, p. 14. 



