310 The Field Naturalist's Quarterly November 



sive than that known as the insects, and few probably call 

 for more especial toil, since the various species of which the 

 whole is built up are, to a very large extent, restricted 

 to certain habits — often to a certain kind of food-plant 

 which, again, is only to be found growing upon certain 

 formations of supersoil. There are three very distinct 

 methods which must be combined in working up such a 

 catalogue, the most important being, of course, genuine field 

 work ; to go out and take the species in the district is the 

 very best and most positive method of knowing that they 

 occur there, though it must be borne in mind that imported 

 species will often turn up. Exactly what is to be con- 

 sidered an imported or an indigenous species must depend 

 largely upon personal opinion. The cockroach, for example, 

 is undoubtedly imported (cf. F. N. Q., ii. 36), and yet it has 

 for so long a time dwelt with us that it is assuredly become 

 a British insect. The great Longicorn beetles, on the other 

 hand, which have been brought from abroad in timber to our 

 port-towns in the larval state, have there hatched out, and 

 been discovered perambulating the quays, cannot be thought 

 truly British by any stress of imagination, simply because 

 they are taken in Britain. In January 1 90 1 a specimen of 

 CorypJiocera elegans, Fab., was imported into Ipswich in linseed 

 from Calcutta ; this is a lovely insect, related to our Rose 

 Beetle, but larger, with a coat of brilliant green, resembling 

 enamel ; in India and Ceylon its caterpillar feeds upon decay- 

 ing vegetable matter ; but, as it has never been " found in 

 Britain " before, and its presence in the linseed was un- 

 doubtedly accidental, it cannot be considered indigenous. 



In working a given district, every part of it, as far as is 

 practicable, should be explored, more especially if the 

 geological formations of one part differ to any appreciable 

 degree, as is nearly sure, in an extended area like a county, 

 to be the case ; the prevalency of species will be found to 

 vary very materially with divergent physical features which 

 are controlled by the subsoil. And the sandy soil, with 

 its sand-loving plants, will always be found the most prolific, 

 at all events among the beetles. 



The second method of compilation is the searching out 

 of local records throughout the whole mass of entomological 



