1904.] 127 



HELP-NOTES TOWARDS THE DETERMINATION OK BRITISH 

 TENTHREDINIDM, &c. (9). 



BY THE REV. F. D. MORICE, M.A., A^-P.E.S. 



ARGINI. 



Ill my last paper I separated Trichiosoma tibialis (the hawthorn- 

 species) from T. IntreiUei (attached to the willow) chiefly by its 

 having the tibiae black or brown instead of yellow. Mr. Claude 

 Morley, however, has been good enough to send me a number of 

 Trichiosma specimens bred from hawthorn, from which it is evident that 

 this character is reliable only for the $ ? — all of that sex in his 

 "sending" having dark tibise, and all the ^ (^ yellow ones. Before 

 attempting to correct my Table, however, I ought to have more 

 materials than at present in the shape of fresh British specimens of 

 tibialis and latreillei ^ ^ . Konow, besides the colour of the tibise 

 which he warns us may be deceptive, gives pilosity-characters which 

 he regards as more important. But I must own I have failed to 

 recognise the " sammtsehwarzen Hinterleibsriicken " ascribed by him 

 to tibialis in Mr. Morley 's ^ ^, though it is sufficiently apparent in 

 the $ ? . All I can do at present is to acknowledge the imperfection 

 of my Table, but leave it uncorrected till I get fresh light on the 

 matter. 



We come now to the remarkable Genus Arge, Schrank (= Hylo- 

 toma, auctt.). Here again I am under the disadvantage that my 

 collection consists mainly of foreign specimens ; and it may be, 

 therefore, that the Tables I have constructed should be modified in some 

 points to make them hold good for the British forms of certain species: 

 e.g., the aberrations of ustulata described by Mr. Cameron as not 

 unfrequent in Scotland are quite unknown to me, and I have had to 

 leave them out of account. As far as my own experience goes, the 

 characters I shall mention for separating ^r$re-species are constant 

 and easy to recognise. But in several cases I know only continental 

 forms of species recorded by Mr. Cameron as British, and it is quite 

 possible that these may differ somewhat from those occurring in this 

 country. 



SYNOPSIS OF BRITISH ARGE. 



1. Abdomen orange-yellow "• 



— Abdomen purplish-blaek, or metallic blue or blue-green, never yellow 2. 



2. Legs entirely dark ; basal half (or more) of upper wing generally fuseo- 



violaceous, costa and stigma entirely of that colour ; pilosity of liead and 

 thorax dark and very short, inconspicuous 3. 



