262 The Scottish Naturalist. 



house or case. This case is made of black excrementitious 

 matter, and is somewhat pear-shaped with the narrow end bent 

 slightly downwards. The door or mouth is at the narrow end, 

 and on the upper side from it run back several ridges to 

 strengthen the case. Two of these run divergently for about 

 half the length of the case, and below these there are sometimes 

 two shorter ridges. Between the two first-mentioned ridges 

 three other pairs run parallel to them, and meeting, form a series 

 of three V's, one within the other, on the back of the case. Oc- 

 casionally one side of a V runs past its own apex and joins the 

 opposite side of the enclosing V. The rest of the surface of the 

 case is comparatively smooth. The length of the case is from 

 5-6-lines, and the breadth at the hinder or broad end \V2-2 

 lines. 



The larva, as mentioned above, is fat and soft, and not un- 

 like a small cockchafer larva in shape. The hinder part is the 

 largest, whence the reason of the shape of the case, which the 

 larva never" leaves. The head is hard and horny, and when 

 the forehead is applied to the mouth of the case, all intrusion or 

 interference on^the part of the ants is effectually prevented. 

 The larva feeds on the spongy material which forms the older 

 part of the hill. When the larva is about to assume the pupa 

 state it fastens the mouth of its case (closing it up) to a twig or 

 other part of the nest, or sometimes to the case of one of its 

 companions (who, if he too is not ready to become a pupa, has 

 consequently to carry a heavy load about with him), and then 

 turns about till the head is at the broader part of the case. 

 This turning is necessary to allow the perfect insect to escape, as 

 the original door of the house is not large enough for that pur- 

 pose, and the beetle finds it easier to break his way through 

 the back wall. 



Among the Diptera, or two-winged flies, I believe there are 

 some species that frequent the ant-hill, but at present I am not 

 able to give very much information as to this. 



In Scotland, then, we have representatives of at least three 

 orders of insects— Lepidoptera, Coleoptera, and Hemiptera — 

 associatedjwith Formica rufa, and not improbably representa- 

 tives of two other orders — Neuroptera and Diptera. No 

 Orthopteronhas been found inhabiting the ant-hill in this country, 

 but in Continental Europe there is a grass-hopper that inhabits 



