20 BEES AND WASPS [CH. 



number and arrangement of the "cells" of the front 

 wings, the shape of the mandibles, the form of the 

 waist (petiole), and so forth. Some of the largest 

 and most common members of this section are the 

 four species of the genus Ammophila (sand-lovers): 

 all four are from three-quarters of an inch to one 

 inch in length, are black and red in colour, and have 

 rather long two have very long and slender waists. 

 Like the Pompilids they dig holes in the ground ; but 

 instead of using their feet and the coxal joints of the 

 legs as tools, they employ only their powerful jaws on 

 this work, scraping and biting at the soil until a small 

 pellet has been detached, then seizing it in the jaws 

 and carrying it backwards up the burrow. On arriving 

 at the surface they dart backwards a few inches and 

 fling the pellet away. It is interesting to note that 

 the coxal joints of the legs of these insects are not 

 enlarged nor flattened like those of the Pompilids, 

 and further that the Ammophilan method of digging 

 with the mandibles is the same as that employed by 

 those of the familiar social-wasps which build their 

 nests below the ground surface. 



The following observations made on A. sabulosa, 

 the largest of our species, will serve to illustrate the 

 habits of these insects. A specimen was detected in 

 the act of commencing her burrow on the edge of a 

 disused sandstone quarry : for nearly an hour did she 

 work carrying out mouthful after mouthful of earth, 



