ig8 Annals Entomological Society of America [Vol. II, 



yellow; the first and second discoidals branching at a distance of one- 

 half or slightly more than one-half the distance from the tip of the 

 wing to where the third branches. (PI. XXVII, Fig. 1). The first 

 discoidal of the hind wing is very faint and invisible in some specimens 

 in balsam (PI. XX\'II, Fig. 5). In alcoholic and balsam mounted 

 specimens the legs are brownish and the tarsi black ; the femur of eacli 

 fore leg bears a prominent projection on the anterior side near the 

 distal end (PI. XXVII, Fig. 2). Abdomen covered with a white 

 pulverulence which is easily rubbed off, and when it is removed the 

 color of the dorsum varies from greenish yellow (in recently emerged 

 adults) to brownish red (in the older ones) . On the dorsum is a single 

 prominent dusky to blackish, double tubercle, apparently borne on 

 the third abdominal segment (PI. XXVII, Fig. 6). Cornicles dusky 

 to black; specimens examined immediately after mounting in balsam 

 showed the apical half black and the basal half brownish ; incrassate 

 (dilated at the base) and the opening slightly flaring; not reaching to 

 the tip of the abdomen (PI. XXVII, Fig. 7). Style pale yellowish and 

 globular, with a bifid anal plate. (PI. XXVII, Fig. 8). 



Measurements: Length of body, 1.54 — 1.97, avg., 1.73 mm.; 

 width, 0.64 — 0.75, avg., 0.70 mm.; length of wing, 2.82 — 3.29, avg., 

 3 00' width, 1.04 — 1.22 avg., 1.10 mm.; total expanse, 6.3 — 7.0 mm.; 

 antenna, I, 0.15; II, 0.068; III, 1.00—1.22, avg., 1.15; IV, 0.68—0.86, 

 avg., 0.78; V, 0.73—0.89, avg., 0.82; VI, base, 0.13; filament, 1.75— 

 1.9, avg., 1.82; average total, 4.918 mm.; cornicles, avg., 0.32 mm.; 

 hind tarsus, 0.14 mm.; style, 0.11 mm. 



Pupa: — Light yellowish white to very pale greenish, with a 

 longitudinal green stripe on each side of the abdomen. Cornicles 

 pale greenish. 



Described from 6 winged specimens (collected at St. Louis, 

 Mo., June 30, 1908), on two slides, mounted in balsam from 

 alcohol, and 5 'winged and 5 pupae (collected at St. Louis, Mo., 

 May 15, 1908) on two slides, living specimens mounted direct in 

 balsam, and 9 winged (collected at St. Louis, June 13, 1906), on 

 one slide, living specimens mounted direct in balsam. All col- 

 lections made by Mr. J. T. Monell, to whom the writer has the 

 pleasure of dedicating this species. Two type slides deposited in 

 the Illinois State Laboratory of Natural History as Accession 

 No. 40469, one in the U. S. National Museum as Type No. 12630, 

 and two in the writer's collection. 



Idiopterus genus novum. 



lndi\'iduals in this genus are small. The head and antennie 

 similar to those of Phymatosiphum. Antennae, set on large con- 

 spicuous and approximate frontal antennal tubercles (PI. XX\^II, 

 Fig. 9) ; longer than the body; segments I and II stout and robust, 



