No.ioio. NORTH AMERICAN THYSANOPTERA— HINDS. 185 



long and slender, but not very eonspicuoiis; those on three to tive 

 ne:ir(>i' the niidcUe than usual. Color of one, two, live, six, and seven 

 blown like head; three and four pale yellowish or gray; four shaded 

 slightlv with brown, increasing toward tip; basal constriction of live 

 yellowish. 



Frothorax not longer and but very slightly wider than the head, 

 nearly square, without stout spines upon fore angles but with two 

 long spines at each hind angle. Mesothorax about one and one-half 

 times as AV'de as head, slightly wider than luetathorax; greatest Avidth 

 at hind edge; color reddish or orange-brown. Wings reaching 

 usually beyond the tip of al)donien, al)out one-seventeenth as broad as 

 long; fore w:ing with two longitudinal veins; the origin of tlie hind 

 vein indistinct; neither vein heavy; costa set with about twenty quite 

 long spines l)esides the fringe hairs; fore vein bears ten to twelve 

 rather weak spines and the hind vein about thirteen similar spines. 

 Legs I'ather short; fore femora slightly thickened; yellow to gray- 

 brown, bases of bladders dark brown; spines small except ros\' of 

 eight or nine on inner side of hind tibite. 



Abdomen nearly cylindrical and long, two and two-thirds times as 

 long as wide; but vei y slightly wider than mesothorax; last three 

 segments very short and tapering Aery al>ruptly to the acute apex. 

 Color pale yellowish or grayish brown, Aery much lighter than thorax 

 and head; ninth and tenth segments shading to ])roAvn-black; inter- 

 segmental membranes pale yelloAvish or gray. Segments not over- 

 lapping; receptaculum seminis placed far back beneath eighth dorsal 

 plate, very conspicuous, bright orange-red; ovipositor indistinct, 

 vestigial; tenth segment split open above and sides nearl}" meeting 

 beneath; anal spines long, slender, not A^ery dark. 



Redescribed from seven females taken on grass at Amherst, Massa- 

 chusetts. 



Male unknown. 



Food plants. — Cyperus sp., corn and grass (Iowa), Dactylis glomer- 

 ata^ Panicnm sanguinale., and various other grasses (Massachusetts). 



Ilah'itat, — Ames, loAva; Amherst, Massachusetts. 



These specimens haAe been compared Avith Miss Beach's tA'pes and 

 are identical. The vestigial condition of the OAnpositor. however, 

 misled her into thinking her specimens all males, whereas thcA' are 

 really all females. 



This species is exceptional among the Terebrantia in lacking a 

 functional ovipositor, but it is surely vestigial in this case. The 

 eggs are very large, Avhile the ovipositor is disproportionately short 

 and Aveak, and it seems that it must be impossible for this species to 

 deposit its eggs in the plant tissue. In this respect they thus shoAv a 

 divergence toward the Tubulif era, Avhich lay their eggs Avholly exter- 



