162 f"^"^y' 



THE BRITISH SPECIES OF THE ANTHOMYID GENUS 

 LIMNOPHORA Desv. (DIPTERA). 



BT J. E. COLLIN, F.E.S. 



(Continued from antea, p. 100.) 



Tables of the Species 



based iipon cliaracters exhibited in the males, to be folloived by 



a separate Table of the females. 



Subgenus Spilogona. 



1 (10) Nonnally only three pairs of postsutural dorsocentral bristles on thorax. 



2 (5) Frons wide, being at narrowest part 2-3 times as wide as third 



antennal joint. Frontalia 2-3 times as wide as a frontal orbit. 



In the case of doubt with regard to the characters of this 

 section : — litorea is the only species without posteroventral bristles 

 about base of hind femora, and surda, though resembling contracti- 

 frons, has the abdomen more dorso-ventrally compressed. 



3 (4) Arista subplumose, the longest hairs above and below together about 



as long as third antennal joint is wide. Thorax greyer in front and 

 consequently with the narrow central dark stripe more distinct, 

 liind femora with no posteroventral* long hairs. 



.... ] . litorea Flu. 

 (S . Jowls deep, rather more than a quarter the vertical diameter 

 of eye. The two pairs of vertical bristles distinct from the post- 

 ocular ciliation. Thorax brownish-grey, appearing greyer when 

 viewed from behind, with blacker side patches over the root of each 

 wing and a broad hght grey notopleural stripe. Abdomen viewed 

 from behind usually rather light brownish-grey, the dark patches on 

 second segment larger than on third, and on both segments rather 

 elongate and not much broader behind than in front; fourth segment 

 often somewhat darkened about the middle. Front tibiae usually 

 Avithout a bristle behind ; middle tibiae with a small anterodorsal, 

 and two rather longer posterodorsal bristles; hind tibiae witli 2-3 

 anteroventral, 2 anterodorsal, and 1-2 smaller, less outstanding, 

 posterodorsal bristles. Hind femora with 3-4 anterovential long- 

 bristles towards the tip, but short-haired posteroveutrally. Wings 

 slightly yellowish-brown. Halteres yellow. 



$ . Interfrontalia reaching almost to front of frons. Thorax 

 greyish with a narrow central and two broad broAAuish side stripes 

 (one at each side), these latter each with a tendency to split up into 

 two stripes behind. Scutellum greyish about centre of disc. Abdo- 

 men broad ovate, greyish, with shorter, broader, and more indistinct 

 brownish spots. Bristling of the legs as in the male, but bristles 

 stronger and front tibiae with a bristle behind. 

 Length 5-6 mm. ^ 



* Care must be taken not to confuse the outstanding ciliation of long hairs, so often present 

 about base of hind femora behind, with the posteroventral ciliation. 



