2. TABANUS 367 



describes the stripe as considerably interrupted in T. borealis (thougli I do not place 

 much value on that character). The specimen is rather large for T. maritanus, 

 but that species varies considerably in size. The points that weigh the most with 

 me (in not considering the specimen to be T. borealis) are the entire absence of any 

 pale hindmargins to the abdominal segments (the presence of which is one of the 

 chief characters of T. borealis) and the extreme improbability of an otherwise 

 unrecorded British species being first taken in the male sex only. I also consider 

 Brauer's distinctions between many species of Therioplectes far too vague. 



• 



4. T. luridus Fallen. Tibice mainly tawny. Vertex without any tuft 

 of black hairs. Abdomen with brownish red (not orange-red) lateral 

 markings extending in the male to the second and third segments only. 

 Wings with obviously clouded cross-veins. Frontal triangle of the female 

 shining black. 



^& 



A rather small species, easily distinguished in the female 

 by the shining black frontal triangle. 



S. Head not specially large in comparison with the thorax and abdomen nor 

 broader than in the female, but much flatter than in any other British species 

 because the undersides of the eyes (when seen from in front) spread out at a 

 much wider angle ; frontal triangle glistening grey, almost silvery, but with 

 a slight indistinct blackish streak from the antennae to the eyes ; face and 

 broad jowls entirely pale grey, and the frons and face forming a broad shallow 

 triangle which is twice as wide as high except that the frons extends upwards 

 rather narrowly to a point between the eyes ; face and jowls clothed with 

 abundant long pubescence which is greyish white on the middle part but 

 widely black all down the sides and under the eyes ; back of the head very 

 shallow but with a narrow bare glistening pale greyish yellow rim, behind 

 which (especially on the lower part) is some minute black pubescence, and 

 behind that again some soft pale pubescence, but the minute black pubescence 

 dies out on the upper third of the head and leaves a rather longer inconspicuous 

 pale postocular pubescence which again becomes slightly longer though still 

 inconspicuous on each side of the ocellar space, and on that part there is no 

 sign of any black hairs ; frons in profile slightly produced from the eyes ; lower 

 part of the back of the head hardly inflated but the u])per ])art retreating 

 to the hollowed out actual back of head. Palpi greyish yellow or greyish 

 brownish yellow ; last joint broad and stout, forming a broad blunt oval 

 which is about one and a half times broader than long, and is clothed 

 with hardly dense longish hairs which are almost equally mixed black and 

 whitish ; basal joint clothed with longer nearly all black hairs. Eyes 

 apparently touching for a long space but (as mentioned before) the frons 

 extends a considerable distance upwards and the vertex extends (though very 

 narrowly) downwards so that the actual touching part is only about one-third 

 of the space between the occiput and the antennae ; the eyes are clothed with 

 very dense long blackish brown pubescence, which however appears in certain 

 lights to be brownish yellow, and the pubescence becomes sparse on the hind- 

 margin ; facets all almost equal in size ; in life (according to Brauer) the eyes 

 are green with three purple bands and a reddish lower margin. Antennae 

 blackish brown, but the basal joints (especially the basal one) obscured by 

 light grey dust, and the third joint rather reddish about its base ; basal joint 

 large and bearing abundant long black pubescence (much longer than in 

 T.montanus); second joint with short black pubescence, and neither of the 

 basal joints extended forwards cap-like at its top end ; third joint with a 

 moderate but distinct dorsal hump close to the base. 



Thorax and scutellum shining black, but the thorax with traces of widely 

 separated faint grey stripes ; praealar calli not at all ferruginous. Pubescence 

 abundant, rather long and erect, mainly black but quite in front with only 

 light grey pubescence which is composed of thinner hairs, while shorter thin 

 light grey hairs are scattered sparsely nearly all over the disc and are rather 



