PSOROPHORA SIGNIPENNIS 577 



scales predominate, defining a pale tip and subapical ring ; first joint of hind 

 tarsals largely pale, with a dark tip and dark subbasal ring, the succeeding joints 

 with basal halves pale, apical halves dark ; front and mid tarsi with fourth joint 

 narrowly white ringed at base, the last joint entirely dark scaled. Claw formula, 

 0.0-0.0-0.0. 



Length : Body about 4 mm. ; wing 3.3 mm. 



Male. Proboscis straight, the apical half slightly thickened. Palpi exceeding 

 the proboscis by nearly the length of the last two joints which are long and 

 slender and scarcely thickened ; vestiture of brown and white scales rather irreg- 

 ularly intermixed ; apex of long joint and the last two joints with long black 

 hairs ; bases of last two joints white scaled above. Antennae phmiose, the last 

 two joints long, pilose, the others short, thickened at insertions of the long, 

 dense hair-whorls, sordid luteous ; hairs pale brown. Coloration similar to the 

 female. Abdomen elongate, strongly depressed, with long, luteous lateral 

 ciliation. Wings narrower than in the female, the stems of the fork-cells longer 

 and the vestiture much more scanty, scarcely showing the characteristic mark- 

 ings. Claw formula, 2.1-3.1-0.0. 



Length : Body about 4.5 mm. ; wing 3 mm. 



Genitalia (plate 23, fig. 161) : Side-pieces rounded at tip and about t^vice as 

 long as wide; apical lobe very slightly developed, indicated by a narrow fold; 

 no basal lobe. Clasp-filament stout, swollen, reticulate, a rather long terminal 

 articulated spine. Harpes concave, with thickened revolute inner margins and 

 curved tips widely divided into two teeth. Harpagones with a slender ligulate 

 base and expanded apex bearing five setae. Unci forming a small cone with a 

 revolute margin, no basal appendages. 



Larva, Stage IV (plate 116, fig. 397). Head rounded, wider than long, nar- 

 rowed before eyes, a slight notch at insertion of antenna, front margin broadly 

 arcuate. Antennas long but not extraordinarily so, subcylindrical, slightly 

 tapered, spined on basal two-thirds ; a large tuft at middle ; two long subapical 

 spines, two short spines and a digit at tip. Eyes large, transverse, pointed. 

 Mental plate elongate triangular, longer than wide, a central tooth with four- 

 teen on each side, all much alike, the basal one smaller. Mandible quad- 

 rangular ; a long filament and a short one before tip ; an outer row of cilia from 

 a collar; five small tufts from angular prominences on outer margin; dentition 

 of four teeth on a short process, the fourth longest; a long spine before, two 

 short teeth at base, two broad filaments within ; process below elongate, furcate, 

 with a row of hairs on outer side ; basal angle small ; a row of hairs within ; a row 

 of long hairs at base. Maxilla subspherical, divided by a band-shaped suture ; 

 inner half with two rows of cilia ; a row of long hairs at tip ; outer half with a 

 single large filament at middle next suture. Palpus short and stout, with four 

 irregularly rudimentary digits. Thorax rounded, wider than long; hairs 

 abundant but not long. Abdomen stout, anterior segments shorter. Tracheal 

 tubes broad, band-shaped. Air-tube large, strongly inflated, tapered on outer 

 half, three times as long as wide ; pecten of four teeth scattered on basal fourth 

 of tube, single tooth a long spine with broad base with three or four basal 

 branches, sometimes a short one on the other side. Lateral comb of eighth seg- 

 ment of six scales joined by a chitinous band ; single scale elliptical, with a 

 stout, curved apical spine, a smaller subapical one, and still smaller ones 

 between and below. Anal segment longer than Mnde, ringed by the plate ; dorsal 

 tuft a long hair and brush on each side ; a small lateral tuft ; ventral brush well 

 developed, extending along the ventral line to base. Anal gills long, twice as 

 long as the segment, regularly tapered to a sharp tip, each with a slight central 

 trachea. 



