434 



MAJOR E. E. AUSTEN. 



(^) 



13 (18 



14 (15 



15 (14 



16 (17 



17 (16 

 18(13 



Scutellum not smoke-grey pollinose nor clothed with silvery-white 

 hair, entire dorsum of thorax dark mouse-grey, clothed with 

 blackish hair (abdomen black) ; much larger species, about 20 mm. 

 in length . . . . . . . . . . . . nigrotectus, Big. [2] 



Wings with first posterior cell open. 



Colour of scutellum (and hind margin of scutum) sharply contrasting 

 with that of dorsum of thorax between bases of wings ; principal 

 pale markings on dorsum of abdomen in shape of two transverse 

 bands ; small species . . . . . . . . insidiator, sp. n. [3] 



Colour of scutellum not sharply contrasting with that of thorax 

 between bases of wings, but either identical or at most somewhat 

 paler. 



Dorsum of abdomen beyond the base with paler markings confined 

 to the extreme hind margins of the second and two following 

 segments . . . . . . . . . . . . praemaiurus, sp. n. [4] 



Dorsum of abdomen not so marked. 



Dorsum of abdomen beyond the base with paler markings including 

 or consisting of a series of median triangles or more or less triangular 

 spots, either separate or in part confluent. 



Last two or last three segments of abdomen presenting a sharp 

 colour-contrast with remainder ; pale median triangles, large and 

 broad* . . . . . . . . . . . . siamensis, Ric. [14] 



No colour-contrast between last two or last three segments of 

 abdomen and remainder ; ground-colour of dorsum of abdomen 

 uniform. 



Median triangles or spots on third and two following abdominal 

 tergites more or less confluent . . . . . . finalis, Walk. [5] 



Median triangles on second and three following abdominal tergites 

 widely separate . . . . . . . . . . rubicundulus, sp.n. [6] 



Dorsum of abdomen beyond the base with paler markings including 

 or consisting of a longitudinal median stripe — not triangles or spots, 

 although exceptionally the longitudinal median stripe may take the 

 form of a series of confluent truncate triangles. 



Paler markings on dorsum of abdomen consisting solely of a more 

 or less distinct longitudinal median stripe (no admedian pale 

 markings — not even a sharpl}^ defined, pale spot on each side of 

 second tergite). 



Wings distinctly infuscated (strongly tinged with sepia) . . 



pugnax, sp. n. [11] 



Wings hyaline. 



Wing-stigma conspicuous ; front relatively rather broad (4 to 

 times as long as its breadth between the lower inner angles of the eyes 



pugiunculus, sp.n. [12] 



Wing-stigma inconspicuous ; front narrow (about seven times as long 

 as its breadth between the lower inner angles of the eyes) . . 



agnoscibilis, sp. n. [13] 



Paler markings on dorsum of abdomen, in addition to the longi- 

 tudinal median stripe, consisting of an admedian stripe or an 

 admedian longitudinal series of spots on each side, or at least of 

 a sharply defined pale spot on each side of second segment. 



4i 



* Owing to the completely denuded condition of the type and paratype of T. siame^isis, Ric. 

 (see below, p. 455), the only specimens of this species at present available, the absolute accuracy 

 of this statement as to the triangles cannot be guaranteed, though the ground-colour presents 

 indications which seem to warrant it. 



