HYMENOPTERA. ACULEATA. 211 



springing on its prey (two-winged flies) after the 

 manner of a cat. The eyes in Oxybelus are ovate, the 

 antennae short, the legs thick, ciliated and spined, and 

 the thorax has a sharp curved spine, near the base, which 

 Crabro has not. The wings have but one submarginal 

 cell, from which springs a short nerve as in Crabro. 

 0. uniglumis is black with some white spots about the 

 thorax, the abdomen banded and spotted with yellowish 

 white, the legs black, reddish brown, and yellowish white. 



In the genus Diodontus, the head is wider than the 

 thorax, the abdomen attached by a very short stalk, 

 eyes ovate, wings with two submarginal cells. The in- 

 sects are small and black, with a little colouring about 

 the legs. They prey upon aphides, and burrow in rose and 

 bramble stems, or in sandbanks. One species, D. minutus, 

 has colouring on the thorax, and yellow mandibles. 



Pemphredon contains only one species. P. lugubris 

 (PL VIII., fig. 2), an exceedingly common insect, is 

 black, from J to | inch long, with a large head and 

 a small glittering abdomen, which is attached to the 

 thorax by a long and curved peduncle. The wings 

 have two submarginal cells. It burrows in decaying 

 wood, and has been observed by Mr. Smith to " settle 

 on a rose tree, and scraping a number of aphides into a 

 ball, fly off with it, carrying it in front of its anterior 

 legs and under its head." 



Mimesa equestris, a very pretty little insect, about 

 J inch long, is black, with the middle part of the small 

 petiolated shining abdomen red. It seems not to be 

 common except at Lowestoft. In the male the abdomen 

 terminates in a spine, curved upwards. In this genus 

 the submarginal cells are three. 



The eighth and last family, Philanthidae, consists of 

 p 2 



