Lntoinology of the lUiTiois River. 229 



?nedian line; aiiiiuli very pale except on the last two 

 or three segineuts ; last segment white basally, remainder 

 covered with dull blackish microscopic pubescence reach- 

 iug forwards to the anal prominence, a triangular ex- 

 tension each side of middle above often a small spot 

 accompanying each; respiratory tube whitish, spine some- 

 times projecting. 



Tracheal trunks sinuate posteriorly, crossing and re- 

 crossing in front of middle. 



Pupa. — Length 9-10 mm., diameter 2 mm. Light 

 brownish ferruginous, obsoletely transversely wrinkled, 

 head and thorax shining, abdomen duller. 



Antennal sheaths not very thick at base, surpassing 

 the marginal angulation above them; carinated tubercles 

 not prominent, lateral notches broad and shallow, palpal 

 sheaths indefinite, rather distant; setiferous tubercles 

 scarcely darker; ocellar tubercles replaced by pale dots. 

 Rima of thoracic spiracles strongly elevated from inner 

 side, so that the fiat top of the prominence is nearly 

 vertical, the upper edge of the rimal border forming a 

 sharp carina and its anterior extremity ending at the 

 tip of the marginal extension in an acute angle ; the free 

 lower edge is crossed by sharp ridges, giving it a serrate 

 profile; rima less curved at middle, more strongly at 

 each end, scarcelv hooked ; inner notch with radiating 

 striations. 



The abdominal fringes consist of a single row of pale 

 spines on each segment, rather long except dorsally on 

 the second, where they are shorter and thicker. The ab- 

 dominal spiracular tubercles arise from a slight eleva- 

 tion, tapering from a comparatively small base as far as 

 middle, thence nearly cylindrical to apex, which bears a 

 subfircular rima; on anterior slope a small transverse 

 groove, not longer than the rima; tubercle about as high 

 as its basal diameter. Last segment with six nearly 

 equal terminal teeth, their points marking the angles of 

 a hexagon; slender, even constricted at base, twice as 



