2. TABANUS 349 



Abdomen as broad as or slightly broader but hardly longer than, the thorax, 

 rather flattened, rather more pointed at the end in the male than in the female. 

 Pubescence short and inconspicuous, but by its colour assisting to show up the grey 

 spots or flecks which almost always exist in a dorsal row and very frequently in two 

 outer rows ; seventh abdominal segment always with some distinct erect black 

 bristly hairs on its underside. 



Legs simple, but with two apical spurs on the middle tibise ; front coxae long, 

 being fully two-thirds as long as the femora ; hind tibiae rather ciliated ; femora 

 dull, clothed all over with soft pubescence except along the underside of the 

 front femora and on a streak behind the apical quarter of the hind femora, these 

 parts being bare and usually shining ; the bare part of the underside of the front 

 femora minutely transversely striate and margined anteriorly with minute black 

 bristles ; * front tibiai about the tip and the front tarsi beneath or about the sides 

 with peculiar " touch-hairs," which are analogous to those in the Lejdidoe. 



Wings (in European species) rarely spotted or marked in any way, and with 

 scarcely any deviation from the typical form of the Tahanidce (fig. 211), except 

 that the upper branch of the cubital fork has sometimes {Atylotus) a recurrent 

 veinlet near its base (fig. 215) as in many Bomhylidce and Asilidai ; posterior cells 

 normally all open, but the first one sometimes narrowed or even occasionally 

 closed ; anal cell closed ; wing-membrane rippled all over, practically glabrous. 

 Alulte strongly developed, and so large that when the wings are at rest they are 

 pushed upright against the sides of the scutellum. Squamae very well developed, and 

 with darkened margins which bear a short ciliation except on the alar pair near the 

 angle where there is a conspicuous tuft of long hairs ; thoracal pair largest but 

 outspread or elevated and not concealing the halteres. Halteres moderate. 



The larvae live in damp earth, in sand, or under rotting leaves and stalks on damp 

 earth ; M. Lecaillon (Ann. Soc. Ent. Fr., Ixxiv., 20, 1 905) has described how T. 

 qiiatuornotatus lays its eggs in a cluster on stems, and how the larvae feed on dead 

 or decaying animal or vegetable matter, and that they can live in almost any degree 

 of moisture from dry earth to absolute water. Hine has also recently bred several 

 North American species as I have noted under the description of the family (p. 322). 



The flies occur commonly around pasturing animals or sit on tree-trunks, 

 and the bloodthirsty females rarely attack though they continually threaten human 

 beings ; the males may be seen sitting on rails or on flowers, and hover in the 

 sunshine at early morn even before sunrise especially in high mountainous regions ; 

 Colonel Yerbury has seen T. distingiiendus hovering during the day time. When 

 confined in a small box the living flies have a remarkable habit of breaking off the 

 tips of the wings and sometimes even the whole wing ; this is probably done by the 

 fly striking its wings against something in its short jerky attempts at flight. 



Tabanus in its wider sense is a very natural genus, but it contains 

 such an enormous number of species (885 in Kertesz's "Catalogus 

 " Tabanidarum," published in 1900) of which many are exceedingly closely 

 allied that attempts have naturally been made to subdivide it, and, as far 

 as British species are concerned, the adoption of Therioplectcs and Atylotus 

 is a great convenience ; about sixty species are known to occur in Europe 

 (and more than double that number are recorded from the Palsearctic 

 Eegion) of which about twenty belong to Therioplectcs and about eighteen 

 to Atylotus (in Brauer's sense of that subgenus) ; fifteen or sixteen species 

 are recorded in this work as British ; more than one hundred and fifty 

 species have been recorded from North America and more than two 

 hundred from South America, about one hundred and fifty from South 

 Asia, over fifty from Africa (excluding Palsearctic), and about fifty from 

 Australia and New Zealand. 



* This character has just recently been noticed by Lnndbeck (Diptera Danica, Part I., 86, 1907) and is 

 wortliy of closer investigation, as it is probable that some specific distinctions will be afforded by it. I had 

 only partially observed it and it is now too late for me to follow it up as thoroughly as I could wish ; it appears 

 to me that the bare under side of the front femora, which is often sunken and margined anteriorly by a close 

 row of minute bristles, is provided as a receptacle for the front tibiaj when the latter are folded against the 

 femora. Lundbeck also calls attention to the intensely black front tarsi of the species of Tabaniis and the 

 peculiar way in which they move the front legs when held in captivity. 



