PSOROPHORA TOLTECUM 589 



Prothoracic lobes moderate, elliptical, remote dorsally, brown, clothed with 

 narrow, curved white scales with a faint violaceous reflection and numerous 

 rather short blackish bristles. Mesonotum deep brown, the two impressed, bare 

 longitudinal stripes visible on anterior edge, concealed beyond by the vestiture ; 

 vestiture of narrow, curved white scales with a faint violaceous reflection in- 

 terspersed in patches among the predominating bronzy brown ones ; the whitish 

 scales occur principally in lunate patches on anterior margin, in spots behind 

 the lateral depressions, along the sides, and particularly about ante-scutellar 

 bare space and above roots of wings; also two indistinct dorsal stripes. Scu- 

 tellum trilobate, gray, clothed with narrow silvery scales, each lobe with a large 

 group of brown bristles. Postnotum elliptical, prominent, dark brown, nude, 

 slightly pruinose. Pleurae and coxae brown, clothed with narrowly elliptical 

 white scales and with rows of short black bristles. 



Abdomen subcylindrical, flattened, posterior segments tapering; dorsal vesti- 

 ture of black and yellowish-white scales, the pale scales forming large apical 

 bands and subquadrate subdorsal patches which leave narrow, black basal and 

 sublateral margins ; the bands uninterrupted on first three segments, posteriorly 

 broken on median line, forming sublateral spots from near base to apex; lines 

 of silvery-white scales on posterior margins of segments laterally to angles, the 

 lateral margins narrowly white scaled except at bases of segments; first seg- 

 ment clothed with dull-whitish scales and with many pale-brown setae; venter 

 with black and pale scales intermixed, the pale ones predominating, the dark 

 ones tending to form apical bands. 



Wings rather broad, membrane hyaline with smoky tinge ; petiole of second 

 marginal cell shorter than its cell, that of second posterior cell of about same 

 length as its cell ; basal cross-vein more than its own lengih from anterior cross- 

 vein ; veins brownish ; scales rather broadly triangular, blackish and dull white 

 intermixed, the dark scales predominating, a small patch of black scales at base 

 of third vein; outstanding scales ligulate, on terminal portion of wing lan- 

 ceolate, mostly dark, but with a number of pale ones intermixed ; fringe entirely 

 dark. Halteres white, the tips slightly dusky. 



Legs moderately long, rather stout ; femora clothed with black and yellowish- 

 white scales intermixed, the white ones predominating ventrally, extreme base 

 and apex and a narrow subapical ring white; tibiae black, with many little 

 white patches ; tarsi black, each joint with a white basal ring, the first joint with 

 a median one in addition, on front tarsi the last two joints, on middle tarsi the 

 last joint entirely black; setae rather long, coarse, and black. Claw formula, 

 0.0-0.0-0.0. 



Length : Body about 5 mm. ; wing 4 mm. 



Male. Proboscis straight, dark scaled, with a pale ring beyond middle 

 Palpi exceeding the proboscis by nearly the length of the last two joints which 

 are long, slightly thickened and upturned; vestiture black, white basally on 

 last two joints, a bare white ring at the false articulation of long joint ; apex of 

 long joint and last two joints with dense, long blackish hairs. Antennae plu- 

 mose; last two joints long, slender, pilose, the others short, with a thickened 

 black ring at the origins of hair- whorls and pale tips ; hairs of whorls abundant, 

 long, brown. Coloration similar to the female. Abdomen long, depressed, with 

 dense and long, pale brown lateral ciliation. Wings much narrower than in the 

 female, the stems of the fork-cells longer, the membrane not smoky tinged, 

 the scaling on the veins less abundant. Claw formula, 2.1-2.1-0.0. 



Length : Body about 4.5 mm. ; wing 3.5 mm. 



Genitalia (plate 22, fig. 155) : Side-pieces more than twice as long as wide, 

 apical lobe well developed, continuous with side-piece, forming a prominent 

 apical angle; no basal lobe. Clasp-filament stout, strongly inflated on inner 



