376 TABANID^ 



bristles on the two basal joints varies ; the amount of black pubescence 

 on the tibiae varies a little ; and the l)elly is sometimes rather obscured 

 on the orange part. Some of the Nethy Bridge specimens of the 

 female have a tendency to be larger, with the third and fourth segments 

 of the abdomen rather darker at the sides and more inclined to black 

 pubescence, while the fifth segment shows very little soft yellow 

 pubescence, and the bright coloring of the abdomen is a little more 

 rufous. A female from Spey Bridge shows the reddish colour on the 

 fourth abdominal segment only by the reddish pubescence. A female taken 

 by Colonel Yerbury at Golspie on June 21, 1904, has the third veinlet 

 from the discal cell (which should separate the third and fourth posterior 

 cells) missing in one wing and very imperfect in the other. 



This species is very closely allied to T. sohtitialis (as I interpret that) 

 but the male may be distinguished by the merely comparatively large 

 indistinctly contrasted front eye-facets, by the shorter browner pubescence 

 of the eyes, by the absence of obvious pale postocular pubescence on the 

 ujiper part of the back of the head, by the larger size and by the less 

 sharply margined orange markings on the abdomen ; while the female is 

 distinguished by the reddish colour on the abdomen extending to the 

 fourth segment, by the darker colored more black-bristled palpi which are 

 thicker at the conspicuous knee-like bend, by the shorter pubescence on 

 the middle tibise, by the rather larger size, and from all species by the 

 ubiquitous soft yellow pubescence on the four basal segments of the 

 abdomen. From even the reddest forms of T. tropicus it may be dis- 

 tinguished by its still more reddish abdomen, shorter haired middle tibiae, 

 less blackened hind tibise and tarsi, and the less black pubescence and 

 tiny bristles on all the tibiae, and its larger less black -bristled palpi, and from 

 all other species it may be distinguished by the predominating bright 

 brownish orange coloring on the abdomen. The North American T. aj^nis 

 is exceedingly closely allied, but has a wider and more equally wide frontal 

 stripe in the female on which is a wider middle callus, and has longer 

 darker antennae, longer rather more equally thick palpi, browner wings, 

 and a more dull orange belly on which the fifth segment and the last two 

 hindmargins are more inclined to be orange; further distinctive notes 

 are given below in the synonymy. 



T. distinrjucndus is one of the commonest British species of the genus 

 Tabanus (in the widest sense) and I have records from Cornwall (Bude), 

 Devon (Torcross, Avon Valley, Stowford Cleeve, and Sidmouth), Dorset 

 (Studland), Hampshire (New Forest), Sussex (Bedgebury Park), Cambridge- 

 shire (Chippenham Fen, common), Suffolk (several localities /. C. Morley), 

 Norfolk (Mundesley), Berkshire (Tubney Wood), Herefordshire (Tarrington), 

 "Warwickshire (Sutton Coldfield), Cumberland (Ullswater), Merioneth (Bar- 

 mouth), Glamorgan (Porthcawl and Crymlyn Bog), and in Scotland 

 Colonel Yerbury has taken it at Nethy Bridge, The Mound, Nairn, Brodie, 

 Kannoch, and Aviemore, while other records include Argyllshire and 

 Arran ; I suspect also that Colonel Yerbury's Kenmare specimens belong 

 to this species ; I can vouch for almost all these records as I have seen 

 the specimens. The dates extend from June 14 to September 2, and it is 

 curious that one of the earliest dates (June 15) is from Nethy Bridge, while 

 the latest (September 2) is from Torcross. Colonel Yerbury has seen 

 the males hovering over roads through woods, and he has stated that 



