PSOROPHORA POSTICATUS 551 



Abdomen subcylindrical, slender, posterior segments tapered ; dorsal vestiture 

 of flat black scales with strong violaceous reflection ; a row of lateral segmentary 

 apical golden spots; first segment with a dorsal patch of violet scales and with 

 many brown hairs ; venter violet-black scaled at bases of segments, apical three- 

 fourths clothed with flat golden-yellow scales, except on distal segments, where 

 the dark scales prevail. 



Wings moderate, membrane infuscated, with strong iridescent reflection; 

 veins brown ; petiole of second marginal cell shorter than its cell, that of second 

 posterior cell about equal to its cell ; basal cross-vein distant from anterior cross- 

 vein about half its own length ; scales of veins black with a blue reflection in 

 certain lights, rather narrow, the outstanding ones towards apex of wing larger 

 and broader, narrowly lanceolate. Halteres pale, the knobs slightly darker. 



Legs rather long and slender, posterior tibiae distally and most of the hind 

 tarsi apparently thickened by dense outstanding scales; femora yellowish 

 towards base ; fore and mid legs otherwise clothed with black scales with a strong 

 blue reflection; knees dull silvery white scaled; tibise and tarsi blue black, 

 except on hind legs, where the last two tarsal joints and the apex of the third are 

 white. Claw formula, 1.1-1.1-1.1. 



Length : Body about 6 mm. ; wing 5.5 mm. 



Male. Proboscis straight, basally slender, slightly and gradually thickened 

 apically. Palpi exceeding the proboscis by nearly the length of the last two 

 joints, which are moderately thickened ; last joint shorter than the penultimate 

 one ; vestiture violet black ; apex of the long joint and the last two with dense, 

 long black setae, a narrow bare white ring at the false articulation before middle 

 of long joint. Antennae plumose, with last two joints long and setose, the others 

 short, blackish at insertion of the long, dense blackish whorls, pale beyond. 

 Coloration similar to the female. Abdomen elongate, strongly depressed, with 

 pale lateral ciliation, the latero-apical golden spots visible from above. Wings 

 narrower than in the female, the stems of the fork-cells a little longer and the 

 cross-veins more nearly in line; vestiture sparser. Claw formula, 2.1-2.1-1.1. 



Length : Body about 5 mm. ; wing 3.7 mm. 



Genitalia (plate 21, fig. 149) : Side- pieces expanded, truncate at tip, apical 

 lobe prominent but scarcely differentiated. Clasp-filament small at base, greatly 

 inflated beyond middle, extreme tip again slender, recurved and with a small 

 articulated terminal spine. Harpes concave, the margins narrowly revolute, 

 bearing an apical tooth. Harpagones with a long, slender stem reaching to tip 

 of side-piece, apex a little expanded and bearing a row of about seven stout 

 hooked-tipped setae and a single leaf-like appendage with a recurved tip. Unci 

 forming a tapering plate with revolute margins. 



Larva, Stage lY. Head large, transverse, widest through eyes; antennae 

 long, uniform, spinose, a hair-tuft before middle; dorsal head-hairs in twos, 

 ante-antennal tuft multiple. Lateral comb of eighth segment of seven scales, 

 attached by their pointed bases to a small chitinous plate, each large, with 

 lateral spines and a long central one. Air-tube inflated, fusiform, with a pecten 

 of four small separated teeth near the base ; hair-tuft rudimentary. Anal seg- 

 ment longer than wide, ringed by a chitinous band ; dorsal tuft of a hair and tuft 

 on each side ; lateral hair minute ; ventral brush distributed along ventral line 

 nearly to base. Anal gills long, equal, pointed. 



Goeldi has figured and described the eggs, obtained from captured females. 

 He did not succeed in obtaining larvae, apparently because the eggs must remain 

 dormant for some time in a desiccated condition. The eggs show the same 

 coarsely spinose surface as those of the other members of the genus. The larvae 

 live in temporary rain-puddles. Dr. Grabham found them in a temporary pool 

 in the forest. Mr. Busck got them in open pools at Arima, Trinidad. Mr. Knab 



