3J2 Syiphidae. 



and at the hind margin of the third segment; first segment bluish, 

 shining. There are three pairs of yellow lunules, about as in luniger; 

 the first pair triangular, not lunulate, and just reaching the side margin 

 at the upper corner, second and third pairs isolated from the margin: 

 the fourth segment has a yellow hind margin, the fifth likewise and 

 also basal corner spots, or it is yellow with a black, transverse spot. 

 The hairs on abdomen follow mainly the ground colour, but at the 

 base and between the lunules are some pale hairs; at the sides the 

 hairs are long and yellow at the base, for the rest short and black. 

 Venter yellowlsh with black or brown, transverse spots on the seg- 

 ments; it has long, pale hairs, at the apex are short, black hairs. 

 Genitalia small, black and reddish, with black hairs. Legs yellow, 

 anterior femora with about the basal third, hind femora with about 

 the basal half or two thirds black; tarsi brownish, last joint paler and 

 middle metatarsus more or less yellow. The long hairs on femora 

 considerably black but pale at the base, on hind femora only black 

 at apex; the short hairs black on the anterior side of hind femora, 

 and mostly on hind tibiæ, for the rest yellow. Wings hyaUne; cubital 

 vein slightly curved but not or scarcely more than in luniger. Squa- 

 mulæ whitish with a pale yellow margin and fringe. Halteres pale 

 yellow. 



Female. Vertex black, shining, the black space about quadrate; 

 frons somewhat arched, the usual transverse depression slight or quite 

 wanting; there are somewhat large, yellowish grey dust spots, between 

 Avhich is a short and often vague or almost wanting prolongation 

 from the black vertex, stopping long before the middle; the frons for 

 the rest dark yellow, often with two more or less distinct, brown 

 spots above the antennæ; the hairs black. Abdominal markings a 

 little narrower than in the male. Legs as in the male, hind femora 

 with only the basal third or half black; tarsi, especially front tarsi, 

 somewhat flattened. 



Length 11,5 to fully 12 mm. 



This species is not unlike L. pyrastrl or seleniticus but is at once 

 distinguished by the bare eyes. 



S. arcuatus is rare in Denmark, and it is curious that it seems 

 to have been more common in earlier time, as I know about twenty 

 specimens, all taken many years ago but none more recently ; vicinity 

 of Copenhagen (Schlick), Ordrup Mose (Stæger), at Sorø (Jacobsen) 

 and in Jutland at Horsens (O. G. Jensen); the dates are ^^/s — ^"/7. 



Geographical distribution : — The species occurs (if correctly deter- 

 mined) in Scandinavia to the northern parts, and on Iceland; it is 

 otherwise recorded from various parts of Europe, and also from Green- 



