356 Miss G. Eicardo on the Tabaninre 



There is an imperfect male specimen from Galagedara, 

 Ceylon, Jnne 1897 (E. E. Green), 11)03. 150, wliich appa- 

 rently belongs to this genus, but will form another species, 

 having a yellow abdomen ; the antennae are placed on a 

 similar tubercle and seem of an identical shape, but the third 

 joint is wanting. 



The specimen named by M'alkcr Cltnjaops paralle/us, and 

 referred by me doubtfully to Diac/iiorus [see Ann. & Mag. 

 Nat. Hist. (7) ix. p. 372 (1902)], from Batjan Island 

 (Batehian) (Wallace Coll.), may possibly belong to this 

 genus ; but the antennae are wanting, the formation of the 

 forehead, of the antennal tubercle and face, besides the shape 

 of the abdomen and legs, agrees with that of the species 

 described above. 



DiACHLORUs, Osten Sackeu. 



Dtachlontx, Osten Sacken, Mem. Boston Soc. ii. p 475 (187(3). 



Jjiabasis, Macq., Hist. Xat. Dipt. i. p. 207 (1834); id. Di])t. Exot. i. 

 p. 150 (1838) ; Loew, Dipt. Siidafrik. p. 31 (1860). {•' Diabasis'' 

 being already occupied in Coleoptera, the name wa^ changed by 

 Osten Sacken.) 



This genus was formed by ^lacquart for the exotic Tabani, 

 bicinctus, glaher, globicornis, Wiedem., and curvipes, Fabr., 

 presenting as he thought an intermediate conformation 

 between Tahanus and Chrysops. The described species are 

 all from S. America, with the exception of D. ferrugatus 

 from N. America, D. scutellatu from Central America, and 

 D. jlavipenn'is from the Philippines. Loew distinguishes 

 it from Lepidoselaga and Selasoma by the absence of 

 metallic colouring or scales and from Tahanus by the curved 

 fore tibiie. Osten Sacken considers it is only distinguished 

 from Tahanus by the shortness of the face, the rather low 

 insertion of the autennte, and the rather broad fore tibiae, 

 tlie coloration of the eyes also differiug from that of Tahanus, 

 at least in D. feirugatus. The greater length of the first 

 joint of the antennae, the general appearance, more slender 

 build, and the markings of the wings seem to sufficiently 

 distinguish it from lahanus, in addition to the curved dilated 

 fore tibiie, as also the absence of any tooth or real pro- 

 jection on the third joint of the antennae. In this respect 

 the species of this genus may be confused with the smaller 

 Tabani, in some of which the projection or angle of the third 

 joint is verj' slight, so that there is very little difference in 

 the shape of the third joint. Bigot thus confused specimens 

 of a Tsorth-American Tahanus and called it D. hcemalopotides. 



The five species placed in this genus by Bigot all belong to 



