HOW THE MELLINUS CATCHES FLIES. 345 



in search of the proper food for her young. This eorsists of 

 vai'ious Dipterous insects. Species of various gen sra are equally 

 adapted to her purpose. 



' It is amusing- to see four or five females lie in wait upon a 

 patch of cow-dung until some luckless fly settles on it. When 

 this happens, a cunning and gradual approach is made. A 

 sudden attempt would not succeed, for the fly is the insect of 

 quickest flight, and therefore a degree of artifice is necessary. 

 This is arranged by running past the victim slowly and ap- 

 parently in an unconcerned manner, until the poor fly is caught 

 unawares and carried off by the Mellinus to its burrow. The 

 first fly being deposited, an egg is laid, the necessary number 

 of flies are soon secured, and her task is completed. Some- 

 times she is interrupted by rainy weather, and it is some days 

 ere she can store up the quantity required. 



' A larva found feeding became full-fed in ten days ; six 

 flies were devoured, the heads, harder parts of the thorax, 

 portions of the abdomen, and the legs, being left untouched. 

 The larva spins a tough, thin, brown, silken cocoon, passes the 

 winter in the larval state, changes to the nymph (or pupa) on 

 the approach of summer, and appears about the beginning of 

 autumn in the perfect state.' 



The mandible of this insect is shown at Fig. c, the labium 

 at d, and the maxilla at e. Only two British species of the 

 genus are known. 



In consequence of the vast number of British Hymenoptera, 

 we are forced to select a comparatively few examples, taking 

 those which afford the best types of the different families. 

 We now come to the family of the Crabronidse. In them the 

 head is large, and frequently of very great size in proportion 

 to the body. The shape of the abdomen is extremely variable, 

 sometimes having a foot-stalk and sometimes none ; while it 

 may be either oval, elliptical, or club-shaped. The eyes aie 

 oval, and sometimes have an impression on one side, which 

 gives til em somewhat of a kidney sliape. 



On Woodcut XXXIV. Fig. 4, is drawn Crabro quadrimacu- 

 latus, one of the most common of its kind. In consequence of 

 the great number of species in this genus, nearly forty being 

 already known, 'Sir. F. Smith separates them into several 



