2. TABANUS 381 



Osten Sacken did not admit that Brauer had properly interpreted his 

 subgenus, and I know that Bigot had not the most elementary conception 

 of it. Osten Sacken had however been misinformed aljout the coloration 

 of the eyes in the female, as in all the living specimens (A.fulvus and 

 A. latistriatus) I have been able to examine the opalescent eyes show a 

 few irregular shifting spots (according to the point of view) of a very 

 distinct nature from any others of our inclusive genus Tahanus 

 (figs. 233, 234); there is however a single slight cross-band in A. latistriatus, 

 but certainly not always in A.fuhus. 



The British species may be easily distinguished from any others of the 

 inclusive genus Tahanus by their mealy appearance, total absence of 

 ocelli, bright orange antennse, and by the recurrent veinlet near the base 

 of the upper branch of the cubital fork, though this last character is said 

 to be occasionally absent. 



TaUc of Species. 



1 (2) Abdomen brownish orange with a broad blackish dorsal stripe. 



Femora in the male on at least the posterior pairs orange on at least 

 the apical liaK, and in the female orange with only the base grey. A 

 brilliant golden-hued species in life. 



7 fuhus. 



2 (1) Abdomen greyish brown (or partly fulvous) with two blackish 



dorsal stripes separated by a rather broad ashy-grey stripe. 

 Greyish brown species in life. 



3 (4) Abdominal blackish stripes bowed out. 



Femora with only just the tip yellow. Frontal stripe of the female 

 narrow and parallel-sided. 



8 msticus. 



4 (3) Abdominal blackish stripes not bowed out. 



Femora with almost the apical half yellowish. Frontal stripe of the 

 female rather broad and not parallel-sided. 



9 latistriatus. 



The tAvo latter species are very closely allied, and are now for the first time 

 closely compared. A. plebeius will probably occur in Britain, as it has been found 

 in France and Denmark, and may easily be distinguished by its smaller size, long 

 postocular pubescence, and general pilosity. 



7. A. fulvus Meigen. Golden-hued species. Femora orange on the 

 apical half in the male, or almost to the base in the female. Abdomen 

 mainly ferruginous. 



A very handsome golden-tinted fly when alive, very distinct 

 from any other British species. 



d . Head very much arched, considerably wider than the thorax, and larger (though 

 often only a little) than in the female. Face, including the side-cheeks, 

 pale greyish yellow with a tinge of green, bearing short dense yellow pubescence 

 which becomes longer about the mouth and jowls ; back of the head deeply 

 hollowed out behind the eyes and with only a microscopical brownish yellow 

 postocular fringe ; vertex greyish yellow with its point blackish, small but 

 distinct, and with some distinct though short brownish yellow pubescence 

 on and just behind it ; frons pale greyish yellow, quite bare, depressed for a 



