242 [November, 



the same time assigning tlie latter as the male of v. Roser's costalis. 

 Whilst axillaris, the species with the shorter costal swelling, he 

 considered (rightly) to be a female and identical with costalis, v. Ros. 



I recognise at this late date that the table has been rather 

 clumsily drawn. It would be more natural, and simpler, were the 

 5 species (costalis, brunneipennis, tumida, suhtumida and denotata) 

 with swollen costse in the female to be grouped together. This 

 swelling begins in all just outside the basal cross vein, and extends, 

 except in costalis, to the end of the costa. It so encroaches on the 

 costal cells in the first 2 named, that its width at the point where it 

 is joined by the 1st thick vein is distinctly greater than that of the 

 cell ; in the other 3 species the cell is much the wider of the two. 



Tumida. — A common autumnal insect, occurring also, but less 

 frequently, in the early part of the summer. Both sexes are readily 

 identified, the male b}' its peculiar blunt-ended abdomen, quite unlike 

 that of any other species I know, and the female by its moderately 

 swollen costa and long fringe. This swelling, though moderate, is 

 quite evident when the wing is seen in full, but may be overlooked 

 if it be turned edgeways. The male hypopygium by its cylindrical 

 shape, erect hairs, and minute anal organ agrees with the type present 

 in denotata, discreta and nudiventris. 



Denotata. — A rare species ; 3 specimens only, all from Stoke 

 wood, the dates being ^J G/8/08, ? ? 8/6/06 and 25/6/06. The 

 thickening of the costa almost amounts to a deformity, and is equally 

 noticeable seen full or edgeways. As founded upon the female, 

 denotata is without doubt a good and distinct species, but it is open 

 to question whether the male I have placed with it rightly belongs 

 there, and is not rather something else and possibly a large and dark 

 form of discreta. Its size, however, fits neither well, being too small 

 for denotata and too large for discreta, whilst an obscure reddish tinge 

 in the black thoi'ax is much against denotata and rather in favour of 

 discreta. 



Discreta. — Five males only ; taken by sweeping the heads of 

 Angelica sylvestris at Tarrington 30/8/06. A tiny little species, 

 related by its hypopygium to midive?ttris, &c. It is one of the few 

 species in which the length of the costa varies beyond the limits 

 allowable to the influence of sex. 



Fusca. — Not a common species. Found most often in the autumn, 

 and very rarely in early summer. 



