76 A. E. GIBBS —SIREX NOCTILIO AND S. GIG AS. 
small specimens from buried wood used to support drain-pipes. 
It appears probable that Miss Ormerod has suggested the right 
explanation, but it will be noted that in the present instance the 
heap of fir-wood in Mr. Kitton’s cellar yielded specimens which, so 
far as size is concerned, exhibit the extremes of variation. 
Other species of 8irex have been taken in this country besides 
the two I have mentioned, but it is doubtful if any of them are 
really British insects. Being wood-feeders the larvae are easily 
conveyed from place to place in timber, and there is no doubt that 
in this way they often travel long distances. The Rev. F. D. 
Morice, M.A., F.E.S., states that he has met with S. gig as in 
TJpper Egypt, where it is certainly not indigenous, and where no 
doubt it arrived in European timber. It is no uncommon thing 
for these flies to appear suddenly in new houses, issuing from the 
woodwork and occasioning alarm among the inmates; and it should 
further be borne in mind that the larvae sometimes remain con¬ 
cealed in timber for years before reaching maturity, and in this 
condition may be conveyed from place to place, making it most 
difficult to trace the land of their origin. 
