112 Records of the Indian Museum. [Vol. IV, 



" India " alone frequenth- being given for Assam; Dr. Annandale 

 informs me in a letter that M. Bigot destro^-ed most of the original 

 labels and substituted others in which onh' " Inde " was written. 

 Owing to denudation it is frequent]}^ difficult to identif}^ species of 

 Tahanus, and probably with the advent of fresh material much 

 rectification may be necessary, especially as regards the identifica- 

 tion of the older species. The synonyms given here are very 

 numerous, but have been chiefly determined from the more 

 important plastic characters, such as breadth of forehead, 

 its greater or less narrowness anteriorly above the eyes, 

 and the shape of the frontal callus; both these characters 

 vary, but to a small extent only ; the shape of the palpi is 

 also a valuable character if not relied upon too minutely ; 

 the absence or presence of an appendix on the wing is a very 

 variable, uncertain, character; the closed or extremely narrow 

 first posterior cell at border of wing appears fairly reliable, 

 but males and females probably vary in this character. Rondani 

 formed the genus Bellardia for species possessing this character 

 (Archiv. Canestr., iii, p. 8i, 1863), but it does not appear a good 

 generic character and has not been adopted by other authors. 

 The design and colouring of the abdomen must naturally be largely 

 made use of, though owing to the easy denudation of the tomen- 

 tose dust which usually forms the spots and stripes, it is often 

 difficult to identify species ; the colouring of the hairs on body and 

 legs is useful, but it appears to vary in specimens of the same 

 species to some extent, especially as regards the legs; the shining 

 polished subcallus m some species appears a reliable distinct 

 character, though here again denudation must be borne in mind. 

 The subgenus Therioplectes, Zeller, formed for species with pubes- 

 cent eyes and with an ocelligerous tubercle on vertex of forehead, 

 appears applicable to the species of the Oriental Region, though 

 their number is very small ; but it is otherwise with the subgenus 

 Atylotus, OstenSacken, formed for species with pubescent eyes but 

 no ocelligerous tubercle, some species such as the widely distributed 

 Tahanus taeniatus, Macq., and other species from this Region have 

 an ^4(v/o/ws-like appearance, that is to say, they resemble the 

 group containing fulvus, rusiicus, and others, of a mealy coloured 

 appearance, Brauer placed black and other species in this group, 

 in his work on European Tabanidae ; but the eyes are practically 

 bare in both sexes, so that this subgenus as in the South African 

 fauna is not here applicable. The grouping of the species has 

 been again attempted as in those of the vSouth African Region, but 

 where it is based upon the presence or absence of spots on the 

 abdomen it. will probably need correction in the future, the group 

 represented b}' Tahanus fumifer, Walker, being one of the most 

 difficult in this fauna. The table of species has been drawn up for 

 the females, only males are included in a few instances where 

 specified; as is always the case, the males in the collections are very 

 few in number. The measurement of the length of the forehead is 

 based on the width anteriorly above the eyes. In the references 



