32 BEES AND WASPS [OH. 



thorax, and Entomognathus by the hairy covering 

 with which its eyes are clad. As a rule the Crabros 

 have large, squarish heads and very large eyes ; and 

 in some the front of the face is covered with very 

 beautiful silvery or golden hairs which glitter like 

 polished metal in the sunlight. The form of the body 

 is very varied : in a few there is a long and slender 

 waist connecting the swollen portion of the abdomen 

 with the thorax ; while in others the waist is quite 

 short, or perhaps hardly distinguishable at all. But 

 it is in the strange forms assumed by the legs, 

 especially by the anterior pair of the males of some 

 species that this genus is most remarkable. Thus in 

 Crabro tibialis the tibiae of the hind legs are ex- 

 traordinarily swollen so as to resemble little clubs ; 

 and the metatarsal joints of the front legs of the male 

 are very long and widely dilated. Again, in C. cetratus 

 we find that the outer edge of the tibia and meta- 

 tarsus of the front leg of the male is spread out in a 

 thin membranous expansion which carries a fine fringe 

 of bristles; while in C. gonager, a small, polished, 

 black species, there are somewhat similar enlarge- 

 ments on the front tibiae, and on the front metatarsi 

 large outstanding shields which are coloured white 

 with three black spots ; the succeeding tarsal joints 

 are also widely spread out. In C. palmarius also the 

 male has conspicuous shields on the tibia and meta- 

 tarsus. Further eccentricities of structure occur in 



