ON THE BRITISH SPECIES OF SIMULIUM. 35 



their terminal edge, instead of only one (these do not show in the figure) . Legs black, 

 except for the silvery patch on the front tibiae, and the hind metatarsi, which are 

 dull yellowish, except at the tip and the extreme base. Front femora with only a 

 little short hair ; front tarsi slightly expanded ; hind metatarsi almost cylindrical 



(fig- 4. d)- 



Female. — Head : frons and vertex shining black ; face silvery grey ; antennae all 

 black. Thorax with integument of mesonotum somewhat shining, with a sub-metallic 

 greenish hue, and clothed with a very fine yellowish pubescence, finer than in the 

 other species of this group ; viewed from in front the thorax has indications of two 

 rather broad greyish stripes which are somewhat divergent posteriorly, but there 

 are no shimmering grey shoulder patches. Pleurae with a small patch of hairs as 

 in the male ; these hairs are less conspicuous than in S. ornatum or S. equinuni. 

 Abdomen black, second segment silvery grey at the sides ; hair on basal segment 

 yellowish ; tergites of last three segments very large and markedly shining (thus 

 distinguishing it from the female of S. tuberosum, with which it might perhaps be 

 confused). Legs : front pair black, the coxae and the tibial patch conspicuously 

 silvery grey, the tarsi about as much enlarged as in S. reptans. Middle and hind 

 legs black, the femora and tibiae more or less reddish towards the base ; the hind 

 metatarsi yellowish, except for the tip, the extreme base, and a line along the under 

 side. Claws (fig. 2, b) all simple, as in S. reptans. 



Time of appearance. — This seems to be a spring species, common in April, May and 

 -early June, and appearing again in August. One specimen in the British Museum 

 series was taken on 1st November. 



Fig. 5. Wings of Sjimulium, x 13; left: 8. latipes ; 

 right : S. hirtipes» 



Distribution. — Essentially a lowland species, with its headquarters apparently 

 in East Anglia. England : Bourne End, Bucks., and Felden, Herts. (P.) ; Sandy, 

 Beds. {E.) ; Cambridge (J.) ; Newmarket and Chippenham, Cambs. (F.) ; Barton 

 Mills, Bungay, Suffolk (V.) ; and Brandon (M.), Ampton, Fakenham and 

 West Stow, Suffolk {N.) ; Wood Walton Fen, Hunts. (E.) ; Sherwood Forest and 

 West Leake, Notts. (Cr.). Scotland : Bonhill and Helensburgh, Dumbarton {K.). 



Habits. — This is evidently an habitual blood-sucking species. The writer was 

 besieged by a large swarm of females on Sandy Heath, many attempting to bite and 

 some actually doing so. Mr. J. C. F. Fryer informs me that it is very troublesome 

 in spring and again in August on Wood Walton Fen and also at Wlcken. In these 

 localities it is worthy of note that there is no running water anywhere in the 

 neighbourhood. 

 (C155) c2 



