138 L-IuHe, 



can capture them, as they are, of all insects, the most difficult to 

 secure. They sneak about under the heather, &c,, where the net 

 cannot be used, and as soon as one comes out into the open it flies, but 

 the flight is a short one, and ihe moment which offers the best chance 

 of success is when it alights again. If it alights on the sand the net 

 should be pounced down over it and the hands should immediately 

 press the ring into the sand, as it will dive under the ring if possible. 

 If it alights on a twig of heather or a bramble bush, the collector 

 must use his discretion as to whether to strike at it or not ; he will 

 have no time to ponder, and the object will be quickl}' secured or the 

 net ruined, in accordance with the skill or the clumsiness of the 

 performer. 



The rarities to be looked for amongst the sand-loving PompiUdcB 

 are Pompilus unicolor and hicolor, both of which may be recognised by 

 having only two submarginal cells in the front wings, and the former, 

 whi^h is the greater rarity of the two, by its narrow head and very long 

 prothorax, its male being entirely black. P. sericeus'i^ another of our 

 greatest rarities, which has not been recognised since F. Smith's 

 time, it is probably a northern species ; it is black, with an arcuate, 

 not angulate, posterior margin to the pronotum. P. WesmaeU, whose 

 (J has a pendent spine from the apical ventral segment ; P. minutulus, 

 whose ^ has its hind tibiae suddenly incrassated towards the apex ; 

 and P. consohrimis, which has the propodeum clothed with fine, erect 

 hairs, and the red segments of the abdomen not margined at the apex 

 with black; are also among the desiderata of most of us. The closely 

 allied genus Saliiis, whose species may be known from those of 

 Pompilus by the serrate posterior tibiae of the $ and the punctured 

 forehead of both sexes, also contributes rarities. S. affinis, recognisable 

 hy its transversely rugose propodeum ; ^S^. nofnfiis, by its black ^ with 

 red femora and black calcaria ; CaUcurffus hi/alinnfus, whose ^ 

 closely resembles that of the preceding, but has long white 

 calcaria, whilst the $ has a broad brown band near the apex of the 

 front wings and the abdomen black and red, and Pseudagenia, which 

 may be known by the white sides of the face in the (J and the large, 

 square, third submarginal cell and the black colour of both sexes. 

 The species of Pompilns and Salius are identical in habits and 

 behaviour, and are often not to be distinguished generically in 

 the net. The two species of Ceropales should be looked for on 

 umbelliferous flowers ; they occur in sandy districts, but are different 

 in their habits to Pompilus ; C. variegatus, with the base of the 

 abdomen red, is a great rarity. Another heath and sand-loving 



