Dorytomus.] RBTXCHOPHORA. 277 



mature ; the thorax also is variable in colour, being pitchy black or red- 

 dish or reddish with dark markings; upper surface slightly shiny, with 

 ashy pubescence, elytra variegated ; rostrum moderately stout, longer 

 than thorax, carinate in middle and striated on each side, but less dull 

 and rugose than in D. validirostrii ; antennae ferruginous with the club 

 often darker ; thorax transverse, rather strongly constricted in front, 

 with the sides dilated and rounded, not very strongly but rather closely 

 and very distinctly punctured, with an indistinct central line, which is 

 more or less plain in front ; elytra with rather strong punctured striae, 

 interstices finely punctured, apex of fifth interstice with a small white 

 patch ; legs ferruginous, femora toothed. L. 3^-4^ mm. 



Male with the antennae inserted nearer the apex of rostrum than in 

 the female. 

 On willows and sallows ; common and generally distributed throughout the king lorn. 



V. costirottrit, Gyll. (bituberculatu*, Zett.). This variety has by 

 many authors been considered to be a separate species, but it can hardly 

 be regarded as distinct : it is larger, on an average, than the type form, 

 and has the sides of the thorax gradually dilated from apex to middle 

 and broadest in middle, whereas in the typ form it is raiher suddenly 

 dilated behind apex and broadest before middle ; this character is, how- 

 ever, often hard to perceive ; the teeth of the femora are, apparently, a 

 little stronger ; Walton, who first introduced D. costirogtri* as British, 

 says that it is very hard to distinguish the species from D. maculate, 

 except by the size and the fact that the latter species appears earlier in the 

 spring and is constantly found on a ditierent food plant, the grey sallow 

 (Salix cinerea), whereas D. costirostris is found on the aspen (Populiu 

 tremula) ; I believe, however, that D. marulatus is found at almost any 

 time, and the differences of the food plant certainly cannot be relied 

 upon, and I therefore prefer to follow Bedel in keeping them together. 

 L. 4-5 mm. 



On young aspens and sallows ; not common ; Esher ; Darenth and Swanscoiube 

 Woods ; Keut; Windsor Forest ; Rnsper; Southsea ; (Jlanvilles Wootton; Coleshill, 

 near Birmingham ; Basrley Wood, Oxou ; Marple ; Agecroft, near Manchester ; 

 Northumberland and Durham district, Gosrorth Woods, very rare; Walton states 

 that he has " received many specimens of D. costirostris from the Rev. W. Little, 

 taken in Scotland, bnt not MCCO a. pained with any of D. macvlatus; also from Mi- 

 ll. X. Greville, who found them rather abundantly on the Lombardy poplar ne-.:T 

 Kdinbnrgh." Dr. Sharp does not mention D. costirostns as Scotch, and it is possible 

 that the records must be referred to the tar. Silbermanni. 



V. Silbermanni, Wenck. This variety differs from the type form 

 in its larger size, less closely punctured thorax, and more strongly 

 toothed femora, and from the rar. eo*tiro*tris in its average larger size, 

 wider shape, thicker and shorter rostrum, and the uniform spots on its 

 elytra. L. 5 mm. 



On willows and aspens ; often under bark in winter ; not uncommon ; Sheernerc, 

 Daren th Wood, Caterham, Dnlwicb, Forest Hill, (fee. ; Mr. Crotch remarks that it 

 seems to be abundant with us in early spring, so it is most likely generally distri- 



