392 TABANID.^ 



traces of an ocelligerous tubercle ; the distinctions are however sufficient 

 to clearly locate our British species. 



This is still an enormous subgenus, even after separating off Thcrio- 

 'plcdes and AtyJotus, and many species are exceedingly difficult to dis- 

 tinguish. Even the very large species, T. hovinus, has been separated into 

 two species which had been confounded for more than eighty years, and in 

 this work I have recorded specimens which do not clearly answer to either 

 of those two. 



TaUe of the Males. 



1 (4) Very large species (20 mm. or more). Abdomen with only a 



middle row of pale dorsal spots. 



2 (3) Eye-facets all about equal. Abdomen obviously tawny about the 



base. 10 hovinus. 



3 (2) Eye-facets enlarged on the front part. Abdomen not obviously 



tawny about the base. 11 sudcticus. 



4l (1) Large(17mm.), or moderately large (12-15 mm.) species. Abdomen 

 with three rows of light grey dorsal spots or flecks. 



5 (10) Occiput with no long postocular fringe. 



6 (7) Large species (17 mm.). Eyes in life without any band. 



12 autumnalis. 



7 (6) Moderately large species (12-15 mm.). Eyes in life with one band. 



8 (9) Abdomen considerably reddish. 13 glaucus. 



9 (8) Abdomen scarcely at all reddish. 14 hromius. 



10 (5) Occiput with a long postocular fringe. Moderate sized or rather 



small species. 



11 (14) Frontal triangle grey, not at all shining (unless rubbed). Eyes in 



life with one or no band. 



12 (13) Antennae mainly ochreous. Palpi elongate oval. 



15 macidicornis. 



13 (12) Antennae blackish. Palpi almost globular. Frons with an 



obvious brown cross-band at the level of the antennae. 



16 cordiger. 



14 (11) Frontal triangle mainly shining. Eyes in life with three bands. 



Palpi elongate. 17 gkmcopis. 



Table of the Females. 



1 (4) Very large species (21 mm. or more). Abdomen w4th only a 



middle row of pale dorsal spots. 



2 (3) Abdomen obviously tawny ; belly considerably orange. 



10 hovinus. 



3 (2) Abdomen scarcely at all tawny ; belly mainly black and grey. 



11 sudcticus. 



4 (1) Large (18 mm.) or moderately large (13-16 mm.) species. Abdomen 



with three rows of light grey dorsal spots or flecks. 



