PSOEOPHORA 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. > J J 



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 plumose, the last 

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

 dense hair-whorls, sordid Meous ; 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, 3.1-3.1-0.0. 



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



Genitalia (plate 23, fig. 161) : Side-pieces rounded at tip and about twice 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 setse. 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 antennae, front margin broadly 

 arcuate. Antennae 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 coUar; 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 wide, 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. 



