8. NEOITAMUS 683 



one pnstero-dorsivl near the last but lilackish orange and less conspicuous ; 

 hind tibiai with three rather strong antero-dorsal (one being near the base, 

 one at one-third, and one at two-thirds the length) and sometimes one or two 

 smaller bristles in between, about three (3-5) almost equidistant nearly 

 postero-dorsal, and two antero-ventral after the middle ; the usual circlets of 

 bristles occur at the tip of all the til)iije and each tarsal joint, and the other 

 usual tarsal bristles are present. Pulvilli long, blackish brown ; claws dull 

 black, but brown at the base. 



Wings hyaline with an indistinct greyish " gloom " over all the tip and 

 the hindmargin, which includes all the veins and the wingmargin there but 

 whose inner limit is indefinite ; wing-veins blackish brown. Squamae 

 brownish yellow, but clearer yellow at and near the margin, and with a 

 moderate pale yellow marginal fringe which is neither so dense nor so long 

 as in many Asilinoe ; thoi-acal squamae only represented by a bare membrane. 

 Halteres ranging from dull yellow to yellowish brown. 



? . Very similar to the male except in the very distinct ovipositor. Abdomen 

 with the sixth and seventh segments deep black, very much compressed, and 

 apparently forming part of the ovipositor, the remainder of the _ ovipositor 

 being similar and about as long as the seventh segment; end piece of the 

 upper part about a quarter the length of the basal piece, with a terminal pair 

 of neither specially long nor specially small lamellce. Bristles beneath and in 

 front of the middle femora rather stronger and slightly more numerous. 

 Length about 13 mm. 



'o^ 



This species may be distinguised in the male sex from all except N. 

 socius by the shining steel blue sixth and seventh abdominal segments. 

 iV. socius has quite distinct genitalia, the claspers being shorter and when 

 seen sideways elongate triangular rather than oblong, while there are no 

 ferruginous processes against the lower lamellae, and the genitalia are 

 altogether more knobbed and more black haired on both themselves and 

 on the sixth and seventh abdominal segments ; the face knob is smaller, 

 the narrow dividing line down the thorax less distinct, and (most easy of 

 all to notice) the tarsi are distinctly more reddish orange at the base ; 

 N. socius is almost certain to occur in Britain but has not been detected 

 at present, though this is not surprising as it was not distinguished from 

 iV. cyanurus until 1871, even though it is common over North and Middle 

 Europe. N. cothurnatus is easily distinguished by its more abundant 

 yellow pubescence and its longer mainly yellow bristles on the legs, by 

 the paler base of the tarsi, and by the distinct genitalia and black sixth 

 and seventh abdominal segments of the male. N. cyanurus varies a good 

 deal in size, and I think that our British specimens average a larger size 

 than those from the continent, but I have not noticed any other important 

 variation in British specimens ; I have observed however that continental 

 specimens from Eger and Marienbad have much longer pale pubescence 

 beneath the hind femora on especially the basal part, while the claspers 

 seem to be more pointed and the penis shorter, the metapleural and 

 hypopleural fans and pubescence entirely yellow, and the halteres pale 

 yellow. The sharply defined yellow coloriug on the tibiae will distinguish 

 N. cyanurus from the British species of any other genus. 



N. cyanurus is sometimes abundant in woods, and I remember seeing 

 it in considerable numbers in Darenth Wood in Kent on June 18, 1868, 

 when specimens were sitting motionless on the ends of leafless twigs until 

 Tortrix viridana flew past, when they would swoop down from their coign 

 of vantage and bring their prey back to the twigs for consumption ; they 

 however did not hesitate to pounce upon fair-sized Gcometrce. I have 



