BACOTIA SEPIUM. 257 



rather long, somewhat similar to those of T. tubidosa in shape. Except 

 close to the base, the costa for the basal two-thirds is very straight, 

 then curves down to a very definite apex ; the inner margin three- 

 fourths of costa in length. Colour (when fine and fresh) of a deep 

 grey-brown, polished and shining, varying, however, to rather paler 

 brownish, whilst the darkest specimen is not quite entitled to be called 

 black. In some lights the wings are unicolorous, in others, there is a 

 definite black mark at the end of the cell. Under a lens, the nervures 

 are usually seen to be darker, especially the transverse ones and those 

 beyond the cell, so that the dark mark is not purely a light effect on 

 glistening scales. (A little fading or rubbing reduces the insect to a very 

 indefinite aspect.) The fringes in two rows of scales, the shorter very 

 slightly darker. All the scales are darker at their tips [a loss of scales, 

 therefore, at once exposes their paler bases, and a difference of flatness 

 of scales (such as might be produced by a difference of setting) alters 

 the aspect for similar reasons] . Antennas with 26 joints, pectinated 

 from 4th to 25th, pectinations spathulate and scaleless. Legs 

 dark, unicolorous, spur on 1st tibia fths length of latter. The fore- 

 wings look fairly solid. The hindwings are less closely scaled, and 

 hence are more transparent, and appear paler and greyer than fore- 

 wings, though really of apparently the same colouring ; the nervures are 

 very visible on hindwings (not on f orewings) , and are darker owing to 

 the scaling being denser on them (and possibly are a little darker in reality) , 

 the fringes also darker (Chapman). Female: The female is similar to 

 that of nitidella, but smaller. It is short, thick "bug-shaped," slender at 

 each end. The head and thoracic segments are small, black and horny. 

 The antennas, short, setiform, naked, and transparent. The eyes 

 round, rather coarsely faceted. Nothing can be made out concern- 

 ing the mouth-parts. Legs short, naked. The prothorax narrow 

 (collar-like), the mesothorax broader, glossy black-brown, with two 

 white lateral spots, the metathorax yellowish -white, finely margined 

 with black. The pro- and mesothorax sparsely haired above. The 

 colour of dried females appears quite black-brown. The abdominal 

 segments weak, the sides thinly haired, with dense, long, fine grey- 

 yellow wool (as in nitidella $ ) about the anus. The six free abdominal 

 segments each carry dorsally a rather long, quadrangular, dark-brown, 

 corneous spot, the three terminal segments form the ovipositor, which 

 is as long as the body. The colour of the body is dirty yellowish-white, 

 never reddish-yellow as in betulina. The " girdle-spots " are narrower 

 than in betulina and nitidella (Speyer). The head ventral, black; 

 prothorax small, black, chitinous, its front edge with a coronet of 

 upright, stiff, whitish-grey hairs, separating it from the head, a few 

 similar hairs appearing to rise from the black chitin towards the front 

 of the mesothorax, the latter black, chitinous, strongly developed ; the 

 metathorax black frontally, and pale posteriorly, appears to present no 

 hairs ; the abdominal segments 1-6 divisible, dorsally, into three parts, 

 (1) a dark coloured front edge (remains of chitinous plate), (2) a 

 depressed central yellowish area with a ring of black scales (greyer 

 ventrally) towards its front edge, (8) a raised posterior edge, slightly 

 flesh-coloured ; the intersegmental membranes bright yellow ; the 7th 

 abdominal segment darker tban the preceding ; the 8th appears to be 

 surrounded witb the close and dense fringe of yellow-grey, silky hairs 

 forming the anal tuft ; there is a distinctly lateral depression directly 



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