64 Orthorrhapha brachycera. 



my dates are ^/e to towards the end of June ; it seems thus to some 

 degree to be a spring species. It has been taken in plantations of 

 Salix, as also recorded by Zetterstedt. 



Geographical distribution:— Northern and middle Europe down 

 into France; towards the north it goes no further than to southern 

 Sweden. 



15. Rh. dentipes Zett. 



1842. Zett. Dipt. Scand. I, 397, 9, et 1849. VIII, 3055, 9. — 1903. 

 Kat. palåarkt. Dipt. II, 224. 



Male. Eves contiguous, frontal triangle very small, grey; epistoma 

 grey. Occiput grey with black hairs. Labrum as long as or a little 

 longer than the head is high; palpi dark, brownish haired. Antennæ 

 about as long as the head, black, the two basal joints slightly short- 

 haired, the third joint elongated, slightly attenuated towards the apex. 

 Thorax grey, almost bluish grey, practically without stripes, only the 

 two interstices between the bristles a little darker. The dorsocentral 

 bristles longish, a little longer behind, uniserial, the acrostichal bristles 

 short, biserial, all black. Further a humeral bristle, a posthumeral, about 

 three notopleural, two supraalar and a postalar bristle, all black; 

 besides there are a pair of bristles in front, inwards to the humeri, 

 and also some smaller bristles are present. Scutellum with four black 

 marginal bristles. Pleura grey, metapleura with black or brownish 

 hairs. Abdomen light grey, with black or brownish, somewhat erect, 



longish hairs. Venter of the same 

 colour, somewhat sparingly haired. 

 Exterior genitalia of a curious shape, 

 the upper lamellæ large, somewhat 

 triangular or pointed oval and some- 

 what spoon-shaped, they are finely 

 grey pruinose, in certain directions 

 Fig. !20. Rh. dentipes, male genitalia. shining almost whitish ; the lower 



lamellæ are broad at the base, 

 tapering into a long and thin. ferruginous apex, in the middle of the 

 upper margin there is a triangular tooth ; they are long-haired, 

 especially long at the apex; between the upper and lower lamellæ 

 there is on each side a small style, perhaps belonging to the lower 

 lamellæ. The eighth ventral segment is arched, and from here the 

 curious penis projects; it is ferruginous, thread-like, sinuous at the 

 base, stretching far backwards and then again curved forwards with 

 the end part. Legs black or brownish black; coxæ greyish pruinose; 

 the hind legs are of a curious shape, the hind femora thickened 



