2. TABANUS 409 



and a half times longer than deep, the dorsal hump (well before the middle) 

 being strongly defined and usually bearing some tiny black bristles ; style- 

 like portion about as long as the basal segment of the third joint. 



Thorax greyer than in the male and with shorter pubescence, which causes 

 the grey stripes to become more obvious ; the depressed light grey pubescence 

 more generally difi"used and more obvious, and the erect black hairs 

 less obvious ; pubescence on the pleurae less abundant. Scutellum greyer, 

 with the erect black pubescence short but rather longer than on the disc of 

 the thorax, and with the depressed light grey pubescence more obvious. 



Abdomen greyish black with three rows of light grey flecks, the middle 

 row forming triangular flecks on the hindmargins (largest and most distinct 

 on the second and third segments) with the front point on the second segment 

 almost reaching to the foremargin but on the third segment only about half- 

 way up the segment ; side-flecks forming sloping trapeziums which do not 

 quite reach the foremargins but which have their outer edge sloping back to 

 the hind corners, so that there is a distinct interval on the hindmargins 

 between the middle and the side-flecks ; these side-flecks are largest and most 

 complete on the second and third segments, though only a little more so than 

 on the fourth segment ; basal corners of the basal segment light grey, but 

 those of the second segment rather ochreous and the sidemargins narrowly 

 grey, and the ochreous corners not quite connecting with the side rows of 

 grey flecks ; on tlie fifth segment the three grey flecks small, and on the 

 sixth segment hardly traceable. Pubescence mainly pale yellowish, short 

 and depressed, rather conspicuous on the greyish parts and occurring as a 

 short fringe on the hindmargins, but short and depressed and black on 

 blackish parts (much more inconspicuous than the yellow pubescence) ; 

 sidemarginal pubescence very short and inconspicuous and pale yellowish, 

 though black hairs occur very near the edge on the fourth and subsequent 

 segments. Belly normally pale ashy grey with a vague darker broad middle 

 stripe and with narrow pale hindmargins of segments and with the adjoining 

 parts of the first and second segments obscurely reddish, but this reddish 

 coloring apparently very variable in extent. 



Legs with shorter pubescence than in the male, especially on the tibia?, and 

 the lateral fringes on the hind tibiae reduced to an antero- dorsal row. 



Wings, squamae, and halteres as in the male. 



Length about 13-5 mm. 



This species varies a little in both sexes in the amount of ferruginous 

 or orange coloring at the sides of the second (or third) abdominal segment 

 and on the belly, but it is a common species which is soon easily recognisable 

 except from T. glaucus. In size it is rather smaller than T. glaucus and 

 compares with only T. maculicornis and T. cordiger, and the male is dis- 

 tinguished from both of these by the absence of any long postocular 

 ciliation, while the female is distinguished from that of T. cordiger by the 

 more linear middle frontal callus, and from both species (or at any rate 

 from T. cordiger) by the absence of any darkened space between the 

 antennae and the eyes; T. iromius is larger and is altogether a lighter 

 yellower colored species (whence the name bromius, coffee colored), and 

 has the sidemargins of the male abdomen more fringed with pale hairs, 

 and the anterior tibiae with less obvious pubescence ; the female has no 

 blackish pubescence (or very rarely) about the upper part of the cheeks, 

 and has a shorter postocular fringe than T. maculicornis. If T. glaucus is 

 a distinct species it is larger and has much more reddish coloring on the 

 abdomen both dorsally and especially ventrally, while its grey abdominal 

 markings are indistinct. 



T. bromius is the commonest British species of even the comprehensive 

 genus Tabanus, though (as in T. autamnalis) my records do not extend 

 north of the Midland counties. I have records from Devon, Dorset, 



