2. TABANUS 347 



hyaline liindmargin, but rather less washed out and the individual hyaline 

 markings wider. Squamte with broader and blacker margins. Halteres in 

 some specimens without any conspicuous whitish tip to the knob. 

 Length about 10-5 mm. 



This species is altogether broader than H. italica and larger than most 

 specimens of 11. pluvinlis, while the abdomen is more elongate than that 

 of IT. crassirornis ; the wings have a less washed out appearance than in 

 H. italica but have none of the muddy yellowish tint of H. plnvialis. 

 Even if a hybrid could be found between H. plnvialis and H. italica it 

 would not be likely to differ from both parents so strikingly in the 

 abdominal markings. 



H. Bigoti ? is at present only known as British from four females 

 taken by Colonel Yerbury in company with H. italica at Walton-on- 

 Naze in Essex from August 11th to 23rd, 1907. 



Synonymy. — When in Paris in May 1906 I was much puzzled with Gobert's 

 species of Ilcematopota and I could not satisfactorily identify them with our British 

 species ; I made a note hoAvever that J/. Bigoti seemed to resemble //. italica but 

 had the wings not much washed out, which would agree fairly well with the 

 Walton-on-Naze specimens. Gobert's description is hopelessly inadequate but 

 not contradictory, and as he gave no indication of sex it is very probable that he 

 also did not recognise the male. 



2. TABANUS (sensu lato) 

 (including THERIOPLECTES and ATYLOTUS). 

 Tahanus Linne, Syst. Nat., Ed. x., T. i, 601 (1758). 



Large moderately pubescent flies of usually brownish black 

 or grey colour, but sometimes Avith brownish ferruginous or 

 conspicuous reddish orange markings and usually with longi- 

 tudinal rows of grey spots or flecks on the abdomen. 



Face broad, with broad cheeks all down the sides which are much more pro- 

 minent than the sunken middle part of the face (= epistoma) and these cheeks bear 

 more or less bushy pubescence which continues on to the jowls and thence to 

 the lower part of the back of the head ; upper part of the back of the head not (or 

 but little) puffed out in either sex ; ocelligerous tubercle present or absent, but 

 never conspicuous, and the actual presence of ocelli doubtful even when the 

 ocelligerous triangle is present. Frons in the male limited to a triangle above the 

 antennae which extends up to a point between the eyes, but in the female this 

 " frontal triangle ''' is continued as the " frontal stripe " right up between the eyes to 

 the vertex, and the parts of the eyes near where the frontal stripe merges into the 

 frontal triangle are known as the lower angles of the eye ; the frontal triangle 

 separated from the cheeks by a furrow running sideways from the lower margin of the 

 antennae and sloping upwards to the eyes ; frontal stripe of the female bearing some 

 spaces (usually black) denuded of dust or pubescence which are known as the frontal 

 " calli," and of these the lower one occupying a position immediately above the frontal 

 triangle, and the middle one placed at about the middle of the frontal stripe and 

 varying specifically in shape (when i)resent) from quadrate to linear, and very 

 frequently connected with the lower callus by a narrow black line ; the upper callus 

 is seldom distinct but often indicated by a blackish or darkened space about the 



