576 THEREVID^ 



which almost cover them, the wings are slightly clouded, the middle of the 

 cubital cell being paler than the rest, and the postical fork especially and 

 the cells near it with slight dark clouds; it was apparently taken in 

 company with normal T. hipunctata and with T. annulata and T. nohilitata, 

 but I do not think it a hybrid though Zetterstedt has recorded the capture 

 of T. hipunctata 6 in cop. with T. annulata ? ; a rather similar female 

 was taken by Mr Lamb at the same place in July, 1906, but a male taken 

 at the same time is indistinguishable by me from ordinary T. hipunctata. 

 Minor variations occur in the relative contrasts between the black and the 

 grey abdominal bands, which are usually rather undefined in both sexes 

 but sometimes well defined or on the other hand very vague in the female, 

 also slightly in the size and shape of the frontal calli, and in the amount 

 of pale pubescence on the front part of the frons which seems to be more 

 extensive when the calli are small. The male cannot be confounded with 

 any other British species, because T. pichcia and T. circumscripta have the 

 abdomen almost entirely black haired dorsally, and the lateral and ventral 

 pubescence not whitish; T. nohilitata has the abdomen with brownish 

 tawny hairs, and T. arcuata in its handsome form has the abdomen with 

 black and tawny bands, or in its form inornata has not the slightest 

 tendency to a whitish pubescence. The female is distinguished from all 

 other British species by the almost absolute character of the divided frontal 

 callus, though I have seen this character in a female of T. nohilitata but 

 that specimen was at once distinguished by the golden brown pubescence 

 on the face and back of the head and by the black haired seventh abdominal 

 segment. Even now I am inclined to believe that there may be a very 

 closely allied species with much more extended black dorsal pubescence on 

 the abdomen and with the upper part of the mesopleural tuft darker ; 

 most (if not all) of the specimens from Golspie and Nairn seem to belong 

 to this darker form, while Porthcawl specimens belong to the lightest form. 

 T. marginula is closely allied but has a still more intensified venation and 

 has a fairly well defined cloud concentrated into a blotch which is partly 

 in the submarginal cell and partly in the cubital fork-cell. 



T. hipunctata is common on sandy banks or dunes, more especially on 

 the coast, but occurs inland in suitable localities. My localities are 

 numerous on the Norfolk and Welsh coasts and extend from Cornwall 

 (Padstow) to Sutherland (Golspie), and from Yarmouth on the east to 

 Barmouth on the west, whilst I have taken it inland at Barton Mills in 

 Suffolk (where however other maritime insects and plants occur). My 

 dates extend from May 30 to August 11. 



Synonymy. — Coucke considers this species to be a variety of T. nohilitata, from 

 whicii however it differs " toio cceloT Walker's diagnosis is practically a copy from 

 Loew, but his English description applies to some entirely distinct species, probably 

 T. nohilitata. Moses Harris' Sylvicola iinicus is probably a synonym as he refers 

 to two black shining studs on the "frontlet," but otherwise his description is 

 unrecognisable. 



7. T, lunulata Zetterstedt. Similar to T. annulata, but the wings with 

 the fourth posterior cell more or less wide open. Thorax with suberect black 

 hairs intermixed in the pale pubescence in both sexes. Halteres blackish. 

 Female with large blackish brown spots (or almost bands) on the abdomen. 



