1021.3 241 



bases of antennae, and the <intennae (though still short) lojigev in 

 propoi'tion to their width. Thorax viewed from in front unicolorons 

 grey, sometimes with a brownish tinge down the lines of acrostichal 

 and doi'socentral bristles ; Viewed from behind this brownish tinue 

 (if present) disappears, while a narrow light slatey-grey stripe be- 

 comes visible on each side of the presntnrnl acrostiehals, and a broad 

 postsutiiral slatey-grey stripe at each side above wing-base. Abdo- 

 men viewed from behind witli quite distiKct, mxnowly trianguhir, 

 b own patches on second and third segments 5 tiiough when viewed 

 from in front these patches cazi hardly be traced. Legs witli 

 ■slightly stronger bristles and hind femora with 3-4 strong antero- 

 ventral bristles towards tip (whereas in vir//o there are only two) ; 

 there are also a few distinct posteroventral bristly hairs about base 

 of hind femora, which are absent in virgo. Wings not so milk- 

 white, the veins darker and the cross-veins somewhat closer 

 together. 



2 . More unicolorous than in male and more yellowish-grey than 

 in viv(jo. The slatey-grey thoracic stripes are less distinct than in 

 male and the abdomen is unicolorous j'ellowish-grey. Structure of 

 h-ead as in male except for the broader frons, with its long 

 interfrontalia (decidedly narrower than in virgo) reaching to front 

 of fious and leaving the black frontalia as two long very narrow 

 triangles with their })oints ending opposite the front ocellus. 

 Cliaetotaxy of legs as in male and with at least cue distinct bristly 

 Jiair at base of hind femora beneath. 

 Length 6-6'5 mm. 



This species is undoubtedly quite distinct from tirgo, though there 



has been some confusion in the identification of the two species. 



All previous records of maritimn as British — including the mention 



by Stein (191G) of specimens from AValtoji and Studland — refer to 



virgo. True maritimn was unknown as British until 1 found it in 



some numbers (though only three were males) at Blakeney Point 



(Norfolk) at the end of July 1920. It was sitting in the sun on the 



sandy mud left damp by the retreating tide. 



2 (1) Presutural acrostichals bi- to tri-serial, with 2-3 distinct stronger pairf=. 



Frontalia practically indistinguishable in male, and reduced to a 



line each side of the very broiul and long interfrontalia in female. 



Abdominal dark patches practically indistinguishable 



.... *20. virgo Villeu. 



J 5 . Most of the distinctive characters of this species will be 



found mentioned in the description oimaritima. The antennae are 



closer together at the base with no distinct "keel " between them. 



In the single male examined the evanescent thoracic stripes differ 



from those of maritima. Viewed from above with the light from 



above the thorax is very faintly four-striped, the middle pair 



occupying the whole space between acrostichals and dorsocentrals, 



but are not so wide as the side-stripes; a broad patch across the 



hinder part of thorax appears darker grey than the stripes ; when 



liewfd right from behind this dark patch ajipears silvery-grey and 



V 



