ORANGE SW;FT. ]81 



are dry and unadhesive, and though white when first 

 discharged, they soon acquire a black colour which 

 makes them exactly resemble grains of gunpowder. 



In some of the species a peculiarity is observable 

 in the structure of the hinder legs. In the male of 

 H. Humuli these members are fumished with a 

 dense tuft of very long hairs which has been con- 

 jectured with some appearance of probability to be 

 partly the cause of its peculiar undulating flight. 

 In the same sex of H. Hectus, the entire tarsus is 

 wanting in the hinder legs, and the tibia is tufted 

 in a similar manner. These insects may be distin- 

 guished generically by the shortness of the antennae, 

 which are usually granulated (in some cases, how- 

 ever, they are slightly serrated), and not so long as 

 the thorax, and by the want of palpi and maxillaa. 

 The females are usually largest, and dissimilar to 

 the male in colour and markings. The latter sex, 

 in the species figured, is of a fulvous colour, the 

 upper wings variegated with chestnut and marked 

 with white lines, one of them near the base placed 

 oUiquely, and forming a right angle with another 

 at the interior margin which extends nearly to the 

 apex ; there is a small triangular dusky spot on the 

 disk. The female is brown, with a whitish patch 

 at the base of the upper wings. 



It is found occasionally in many parts of England, 

 in the months of August and September. 



