1921.] 243 



postsutiiral dorsocentrals, but lias a very silvery frons (moro so 

 tlian in nigripes) : the acrosticlial bristles are rather stronger, 

 biserial, and less numerous, and the abdominal dark patches smaller 

 and usually vrith a faint dark medifin line between them ; there are 

 more than two bristles on the shaft of hind tibiae, and the jtro- 

 sternuni and nodose junction of radial and cubital veins are bare. 

 It stood in Kowarz's Collection under the name of Coenosia pacijica, 

 Schin. 



L. triangula is widely distributed in Britain, specimens having 

 been e.xamined from Kent, Devon, Glamorgan, Worcester, Essex, 

 Suffolk, and the Isle of Arran taken in May, June, and August, 

 while Mr. H, W. Andrews has taken it freely in Co. Kerry (Ireland). 

 2 (1) Four pairs of postsutural dorsocenfral bristles. Middle tibiae 

 witli two posterodorsal bristles. Frons viewed from in front with 

 a silvery-grey sheen *22. niyrijyes Dsv. 



(S . Frons slightly wider than in triunijula and the frontalia witli 

 m»re distinctly convex sides; frontal orbits greyer. Thorax ofttu 

 more distinctly striped. Bristles in front of middle femora on basal 

 h;ilf more distinct. Cubital and discal veins uioie parallel towards 

 tip. 



5. Agreeing with the male, but larger. The frons in the single 

 Continental specimen examined is not so distinctly silvery-grey 

 viewed from in front, but at least the interfrontalia is greyish. 



Length about 3 mm. J; 4'6 mm. $• 



This is a more northern species oi which Mr. Verrall took severnl 

 males at Gairloch (Ross and Cromarty) in June 1884, and Col. 

 Yerbury two males at Aviemore (Inverness) in June 1913. 



Subgenus Limnophoea. 



1 (2) Thorax Avith two broad dark stripes in front followed (in the female) 

 by a broad dark transverse band mimediately behind suture. Arista 



subplumose 23. notata Fin. 



J. Frons about twice as wide as third antennal joint; frontal 

 orbits narrow. Thorax with four pairs of postsutural dorsocentrals, 

 and the dark transverse band connected by a median dark line to 

 the broadly darkened base of scutellum. Abdomen with the dark 

 patches on the second segment triangular but with rounded angles 

 and not very broad, those on third segment smaller and more 

 rounded. The last ventral segment bears on the middle of the 

 hind margin (where the segment is deeply excised) a short trans- 

 verse row of black bristles. Hind femora with only 2-3 antero- 

 ventval bristles towards tip and short-haired posteroventrally. 

 Wings only faintly brownish. Squamae whitish-3^ellow. Halteres 

 yellow. 



5 . Frons a third the width of head and widening out in front. 

 Thorax with the postsutural dark band of the male split up into 

 two broad stripes in a line with the presutural stripes, and with a 

 very small triangular dark mark in front of scutellum. Scutellum 



y2 



