1913.] 18 



may occur without the presence of the other, except that trimmer ana., 

 which is ubiquitous and emerges a Httle later in the season, is certain 

 then to be found with the others. The two summer forms also may 

 occur in the same locality or apart. I think it very doubtful whether 

 the three spring forms interbreed, or whether the summer generations 

 of the two of them do so. 



The material on which these remarks are mainly based has been 

 specially collected by me to supplement the fine series of these 

 particularly interesting insects which are in the collection of Cambridge 

 University Museum. 



Park Hill House, Paig-nton : 



November 24th, 1912. 



HILARA ALBOCINGULATA, sp. n. 

 BY JOHN H. WOOD, M.B. 



A small and delicate species, with long slender yellow legs and 

 simple metatarsi, and remarkable for the white semi-transparent 

 abdomen of the male. 



tj 9 . Thorax and scutelhim grey, the former scarcely shining and 

 indistinctly two-striped ; dorso-central bristles in a single row, acrostichal in 

 two rows and about half the size of the dorso-central; sci^tellum with four 

 bristles. Male abdomen white and semi-transparent, except on the last one or 

 two segments which are more or less black ; female abdomen variable, from 

 reddish-yellow to brown. Male hypopygium black and rather large. Legs 

 yellow, bvit darkened on all the last three tarsal joints ; very long and slender, 

 the tarsi especially so, and armed as in cingulata. Wings almost clear, veins 

 brown and well marked, stigma faint ; the dusky halteres yellow-stalked. 



The male can be recognised at once by its strikingly coloured abdomen ; 

 but the female presents some difficulty, as it bears a strong general resemblance 

 to the female of cingulata. The wholly black antennae (in cingulata the basal 

 joints ai"e red), and the dusky halteres are, however, sure means of distingixishing 

 it, whilst other characters less easy to grasp are the darker and not absolutely 

 dull thorax with its fainter stripes, and the longer and more slender legs. 



It is to be found on the Monnow, after the river has come out 

 from the foot hills of the Black Mountain range to meander for a few 

 miles in an open valley, before being shut in again by high ground on 

 its way to join the Wye. Here occur the shingle beds and deposits of 

 sand which I have found so rich in interesting things, from coast 

 insects, such as Myopina reflexa and Tephritis absinthii, to extreme 

 northern forms as Thereva lunulata and Porphyrops rivalis. Here in 

 such surroundings the insect is to be met with not uncommonly in 



