igii.] G. RiCARDO: Revision of the species of Tabanus. 139 



chamois-leather coloured behind the usual seam, with a small 

 black stripe ; breast sides almost chamois-leather coloured ; 

 scutellum black. Abdomen on the first segment brown, 

 rusty brown on the sides, the second one at the base with 

 an interrupted whitish band and another more wavy one at the 

 apex • from the middle of it the triangular spot proceeds, the third 

 to the sixth each with the same shaped whitish band at the apex 

 and larger triangular spots ; on the seventh the border is hardly 

 whitish ; the three last segments are not at all rusty yellowish ; 

 under side almost chamois-leather coloured, brownish towards the 

 apex, with whitish segmentations. Wings almost hyaline, stigma 

 and four spots brown. Legs reddish; tarsi gradually brown. The 

 fore legs are wanting in the single specimen in Fabricius's 

 collection. A very denuded specimen in the Leyden Museum 

 is of a deep pure brown colour, with no trace of the stripe and 

 spots of abdomen, only the segmentations are yellowish white. 



Tabanus optatus, 9 , Walker. 



Proc. Linn. Soc, i, p. 11 1, 33 (1856). 



Tabanus alboscutatus , $ , Rondani, Ann. Mus. Civ. Genova 

 vii, p. 456 (1875). 



Tabanus equestris, cf $ , v. d. Wulp, Notes Leyden Museum, 

 vii, p. 77, 31. Pl- V, fig. 6 {1885). 



Walker's type, 9 , came from Sarawak, Borneo (Saunders 

 coll.) ; another female in Brit. Mus. coll. from Kajoe-Tanan, 

 Sumatra (Dr. Hagen), and a male from India (Saunders coll.). 

 In Indian Museum coll. a female from Belgatchia, Bengal. 



On comparison of one of the Brit. Mus. coll. specimens with 

 the type of Tabanus alboscutatus , the identity of the two species 

 was at once established. Rondani's type also came from Borneo. 



From van der Wulp's description and figure of wing there 

 is no doubt he was describing the same species, and his description, 

 as being the best one, is given below. 



Reddish, face and palpi pale yellow ; eyes naked ; antennae 

 with the third joint darker ; abdomen with triangular dorsal white 

 spots ; the anterior legs and all femora brownish ; wings at the 

 base and a median band brownish, o» , 9 . Length I5"5 — 17 mm. 



Face yellowi.sh white ; beard of the same colour ; palpi ])ale 

 ochraceous ; front rufous, in the 9 moderately broad, with a 

 brown cordiform spot extending u])wards in a line. Eyes bare, 

 in the a* reddish bronze above, with large facets ; below for a 

 third part and on the outward borders blackish, with much smaller 

 facets, even after having been moistened no trace of cross-bands is 

 to be seen. Antennae ochraceous; third joint infuscated, rather 

 slender and on its upper side with a triangular tooth. Thorax, 

 scutellum and abdomen rufous, the thoracic dorsum a little infus- 

 cated, with indistinct stripes ; hind margin of the scutellum 



