1913.] ^7 



varieties of nearly allied forms ^vitli red elytra, and in fact it was his 

 knowledge of the existence of this confusion that prevented Dr. Sharp 

 from describing the species he has so long been acquainted with. As 

 would be expected from their different habitats, in most cases dissection 

 of the iBdeagus in all these forms proves them to be distinct. 



Bradfield : 



January 3rd, 1913. 



TWO NEW BRITISH SPECIES OP ATHETA. 

 BY NORMAN H. JOY, M.R.C.S., F.E.S. 



Atheta magniceps, J. Sahib. 



Siibparallel, very finely piuictured ; head black, thorax pitchy brown, 

 elytra brown or yellowish brown^ hind body black with apex yellowish, antennae 

 fuscons with base yellow, legs yellow ; head large, nearly as broad as thorax ; 

 antennae slightly thickened towards apex, 4th and 5th joints subqiiadi-ate, 

 penultimate joints moderately transverse ; thorax slightly narrower than elytra, 

 moderately transverse, distinctly contracted behind ; elytra together quadrate 

 or slightly transverse ; hind body with basal segments closely and apical 

 segments very diffusely punctured ; S with under plate of 6th free segment of 

 hind liody roiuided and scarcely projecting beyond the upper plate ; 9 with 

 the under plate liluntly angled in the centre, and with the hind margin set 

 with fine hairs. Length, 2'2 — 2"5 mm. 



I took several specimens of this insect in flood rubbish from the 

 Eiver Truim at Dalwhinnie, Inverness-shire, in October, 1909, and 

 again in 1910, and for long regarded it as an undescribed form. 

 Herr Sahlberg has, however, identified the species for me and sent 

 me one of his specimens for comparison. He reports that it is a rare 

 insect in Finland. Although the 6th free segment of the hind body 

 in both sexes resembles these parts in A. melmiocera and its close 

 allies, A. magniceps could hardly be mistaken for any of these, the 

 head being much larger, and the ^ genitalia are entirely different. 

 In general appearance it is much like A. dehilis, but is on the average 

 smaller ; the antennae are darker in colour, the penultimate joints are 

 less strongly transverse, and joints 4-10 are of a different shape. In 

 A. dehilis these joints have the cone-shaped portion at the apex 

 exceptionally large* (Fig. 1). In A. magniceps the joints are normal 

 in shape (Fig. 2). A. dehilis has the under plate of the 6th free 

 segment of the hind body in the (^ very broad and projecting some 



* This form of antenual joint occurs in A. di/ormis, A fumjicora, and its allies, and some other 

 species of the genus. 



