210 INSECT ARCHITECTURE. 



periodically, and confines its ravages to tlie fir. This insect 

 is said to have been found in the neighbourhood of London. 



On taking off the bark of decaying poplars and willows, 

 we have frequently met with the tracks of a miner of this 

 order, extending in tortuous pathways, about a quarter of 

 an inch broad, for several feet and even yards in length. 

 The excavation is not circular, but a compressed oval, and 

 crammed throughout with a dark-coloured substance like 

 sawdust — the excrement no doubt of the little miner, who 

 is thereby protected from the attacks of Staphylimdce, and 

 other predaceous insects, from behind. But though we 

 have found a great number of these subcortical tracks, we 

 have never discovered one of the miners, though they are 

 very probably the grubs of the pretty musk-beetle (Cerambyx 

 7noschatus)y which are so abundant in the neighbourhood of 

 the trees in question, that the very air in summer is 

 perfumed with their odour. (J. R.) 



Another Capricorn beetle of this family is no less de- 



Capricorn Beetle (Cerambyx Lamia ampulator), rounding off the bark of a tree. 



structive to bark in its perfect state than the above are 

 when, grubs, as from its habit of eating round a tree, it cuts 

 the course of the returning sap, and destroys it. 



