1922.] 181 



small; area of scent-glands, in centre of abdomen, distinguishable by 

 being darker and less dull, and having no stellate hairs ; e^-es ver}^ 

 prominent, facets large and granular ; antennae very stout, third and 

 fourth joints tuberculate, each tubercle provided with a very short, 

 adpressed seta, only to be seen with a high magnifying power ; wing- 

 pads narrow, extending to fourth abdominal segment ; each segment of 

 abdomen, except the two carrying the scent-glands, bearing a conical 

 tubercle in the middle of its hind margin. 



An earlier instar, measuring only 1;^ mm. in length, is as above, 

 except that the wing-pads are quite rudimentary, overlapping one 

 segment only. 



The very curious stellate hairs absolutely disappear in the adult, 

 leaN-ing no representative ; the abdominal tubercles also disappear, and 

 one can only speculate as to the significance and use of these structures. 

 Whatever it ma}' be, it must have something to do with the fact that 

 the dorsal surface of the abdomen is always exposed during larval life, 

 whereas it is always covered by wings and hemielytra in adult life, 

 except when these are opened for flight. In the adult, the upper surface 

 of the abdomen is perfectly smooth throughout, the regularity of its 

 surface being broken by neither hairs, tubercles, nor any other sort of 

 excrescences. The disappearance of the hairs from the venti-al surface 

 would apparently depend upon some other consideration. The presence 

 of stellate hairs would seem to be a specific rather than a generic 

 character, as no such structure is to be seen in the larva of the allied 

 species, D. fricornis Schrk. The spines on the head, on the other hand, 

 do not disappear, but become more pronounced. The cast skin remains 

 black, and is therefoi-e not to be thought of as a colourless and trans- 

 parent film, allowing a deeper layer of colour to show through, but, as 

 itself contributing very largely to the colour of the insect. 



The imago may be found from June to October, but the majority 

 of specimens appear to mature in July. I have found the sexes mated 

 in August, and it seems probable that oviposition takes place in the 

 autumn, the eggs not hatching, however, till late in the spring of 

 the following year. 



1 have always found this insect on furze, of which it sucks the 

 juices ; to this Saunders adds broom ; w^here it occurs it is usually 

 common, being, unlike D. tricornis, gregarious ; occasionally it appears 

 in great profusion, as, for example, in Aug. 1882, when the furze-bushes 

 at Hurst Green, Sussex, swarmed with it. It has also been found in 

 moss (Linnell). Douglas & Scott (Brit. Hem.) also give "under moss 



