2. TABANUS 365 



distinguendus has the fine downy pale pubescence on the abdomen of the 

 female extended on to the fifth segment, the frontal stripe with longer 

 and blacker pubescence, the antenna redder and deeper at the hump, and 

 the palpi larger ; T. solstitialis has the middle tibiae with more pubescence, 

 the eyes with longer and more dense pubescence and those of the male 

 with much larger front facets, and the antennae redder. The continental 

 T. nif/rieornis is somewhat unsatisfactorily distinguished, but has the 

 antennae blacker with the dorsal hump on the third joint very slightly 

 indicated so that the basal segment of that joint appears to be longer and 

 much thinner ; it also has the eyes blackish haired, the tibiae darker, and 

 the abdomen with a broader black dorsal stripe on the three basal 

 segments, with more distinctly three rows of narrower grey flecks, 

 and not at all reddish either dorsally or ventrally. T. burealis is also 

 allied, but the female has conspicuous pale hindmargins on the abdominal 

 segments both dorsally and ventrally, and I think the male also possesses 

 this character to a certain extent ; the eyes of the male are said to have 

 larger facets, and the antennae are more as in T. nigricornis ; the frontal 

 stripe of the female broader at its lower end and consequently the lower 

 callus wider; the palpi of the female thinner about the base, and 

 the general tint of colour more bluish with inconspicuous grey (instead 

 of conspicuous yellow) pubescence, and the dorsal abdominal triangles 

 grey and inconspicuous. Other characters of T. montanus lie in the short 

 pubescence of the eyes in both sexes, and the short pubescence on the 

 frontal stripe of the female ; it varies considerably in size in both sexes 

 but is ordinarily distinctly smaller than T. trojncits, T. distinguendus, and 

 T. solstitialis; the female also varies conspicuously in the amount of 

 brownish red coloring on the abdomen both dorsally and ventrally, and to 

 a certain extent in the distinctness of any ferruginous tint on the prsealar 

 calli. Some males from Loo Bridge seem to be very near T. nigricornis, 

 as the hump above the third joint of the antennae is not very pronounced, 

 while the antennae seem to be long and not much reddish about the base of 

 the third joint, and the belly has a broad blackish somewhat interrupted 

 middle stripe right through from base to tip ; the fourth abdominal segment 

 dorsally has only a small reddish spot. Large specimens seem to have the 

 palpi with a more pointed pendulous tip and with more pale hairs, the 

 thorax slightly striped with the three middle stripes well apart and inclined 

 to curve over and unite in front, while sometimes there are distinct side 

 stripes after the suture ; the scutellum almost covered with greyish yellow 

 dust when seen from behind ; the basal segment of the abdomen with a patch 

 of pale pubescence on each side of the scutellum. Notes on other specimens 

 refer to the presence of fairly conspicuous pale pubescence just above the 

 base of the wings, on the postalar calli, and on the reddish praealar calli, 

 while the antennae sometimes appear to be slightly longer. A rather large 

 male from Kenmare (June 7, 1901) has the sides of the fourth abdominal 

 segment more obviously black and the black dorsal spot longer and wider 

 especially at the hindmargin, so that very little more reddish orange coloring 

 is left than a pair of large spots, while the middle of the large dorsal spot 

 on the second segment is widely greyish orange and the spot is not well 

 extended to the hindmargin, and the middle of the fringe on the second and 

 third hindmargins is more conspicuous and almost forms a shallow 

 triangle. A large specimen from Kingussie (July 20, 1898) has a con- 



