igog] Two New Genera and Species of Aphididae 199 



the remaining segments setaceous, filament of \l the longest and 

 decidedly threadlike; circular sensoria in a row on segments III, 

 IV and V of the winged individuals. Beak comparatively long 

 and slender. Legs long and frail. Wing \-enation peculiar and 

 callipterus-like. Veins with a dark broad border; the stigma 

 with a light central area similar to that in Phymatosiphvim; stig- 

 mal \'ein deeply rounded and the fuscous border touching the 

 discoidal; the third branch of the discoidal is not always distinct, 

 sometimes it being represented only by a brownish triangular 

 patch, by a V-shaped dusky patch (PI. XXVII, Fig. 10), or by 

 distinct veins, but in any case always very short and at the 

 extreme tip of wing. Cornicles cylindrical and slightly ta];)ering 

 from the base, the tips slightly flaring. Style ensiform. The 

 genus, although bearing some Callipterini characters, appears to 

 be closer related to the group Aphidini of Mordwilko. 



Idiopterus nephrelepidis, n. sp. 



This interesting species was first taken in a greenhouse at 

 Western Springs, 111., December 2, 1907, on various kinds of 

 ferns. May 2, igo8, it was found quite common and doing some 

 injury to sword-ferns in a Chicago greenhouse. It is probable 

 that the species is of tropical origin, as it has only been found on 

 ferns in greenhouses. 



Descriptions: Winged viviparous female: Entire body blackish 

 or very dark brown. Eyes black. Beak barely reaching the coxae of 

 the hind pair of legs. Antennae whitish excepting the two basal, the 

 last segments, and the joints, all of which are blackish; S — 10 circular 

 sensoria in a row on III, o — 4 in a row on IV, and 2 — '^ on V; total 

 length, exceeding that of the body, segment I more robust and nearly 

 twice the length of II, III 1-4 to 2-5 longer than IV, IV and V sub- 

 equal, VI (base and hlament) subequal to III and IV together, base 

 VI short and about equal to I in length, the hlament very slender and 

 equal to IV and V together (PI. XXVII, Fig. 11). Legs whitish 

 excepting the joints, which are brownish, and the tarsi wliich are 

 black. Wings quite characteristic, a conspicuous fuscous border 

 along each vein, the stigmal vein is subobsolete, as is also the third 

 branching of the discoidal, which is sometimes almost completely 

 obsolete. Stigma moderately thick, and with a clear central area. 

 Other characters of venation as given in the description of the genus. 

 (PI. XXVII, Figs. 10 and 12). Cornicles cylindrical, shghtly imlnncate 

 at base, about twice the length of the style, and pale excepting the 

 basal portion, which is black.^ (PI. XXVII, Fig. V.\.) Style blackish, 

 nearly twice as long as the liind tarsus. (PI. XXVII, Fig. 14.) 



