162 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvi. 



apparently nine segmented, owing to the division of the sixth seg- 

 ment l)y an o})lique suture at about three-fourths its length. Rela- 

 tive lengths of segments: 



1 9, H 4- 5 6 7 8 



5 8:5 "11 10 10 9.5+3.5 2.25 3.25 



Seu'inents one and two rounded; three to six fusiform. One is pale, 

 almost white; two light brown; three lighter than two; three to six I 

 shading gradually to dark brown, almost black; spines pale and not 

 conspicuous. 



Prothorax but slightly longer and a little wider than the head; 

 sides rounded slightly and without prominent spines. Mesothorax 

 nuu-h Avider than prothorax; fore angles obtusely rounded. Meta- , 

 thorax (juite smoothly joined with mesothorax and tapering gradually j 

 to base of abdomen. Wings usually present in summer generations, i| 

 reduced to mere pads in hibernating females; when present, approxi- ' 

 matelv as long as abdomen, about one-thirteenth as broad as long and 

 tapering gradually; two longitudinal veins in fore wing extending 

 from base to tip; veins quite prominent, being darker than rest of 

 wing. All veins bear a few very small, rather indistinct spines; 

 fringe on fore edge well developed, being nearly half as long as pos- 

 terior fringe. Fore wings shaded with yellowish gray; hind wings 

 nearl}^ w^hite. Legs of medium length and size; stout spines only on 

 inner side and at tip of hind tibiie; legs pale yellow shaded with light 

 gray or brown above on femora and tibia^, and Avith prominent dark 

 brown spot at tip of tarsi within. Pterothorax darker yellow than rest 

 of body, with row of irregular dusky spots on each side close to mid- 

 dle, curving outwardly at both ends. 



Abdomen quite long, cylindrical, widening somewhat at first two 

 segments and tapering from eight to tip; eight to ten sharply conical. 

 Spines on nine and ten short and weak, but dark-colored and quite 

 conspicuous; other spines on abdomen small, pale, and indistinct. 

 Abdomen pale yellow; segments one to seven slightly dusky on top, 

 segment ten shading to dark brown at tip. 



Redescribed from six long-winged and four short-winged females. 



Male unknown. 



Food plants. — Poa pratcmls and Phleuni pratense. 



1 have also found genuine "silver top" upon the following list of 

 grasses at Amherst, Massachusetts, but I can not positively connect 

 this species with all the injury: Poa serotlna, P. neiiiordJis, P. eom- 

 pressa, P. arachniferct, I\ fietcherl^ P. aquatica, P. trivmlh, P. 

 c:vs!.((, AgnMls alha, A. canina, A. stolon If era, A. vulgaris, Festnca 

 olcoll, J< h'teroi)lixjlla, F. elatior, F. ovlna, F. duriuscola, F. ruhra, 

 Panicum crus-galli, P. sanguinale, Elymus striatus^ E. vlrginietis, 

 B ramus erectus, B. inermis, Avenaflavescens-vera, Agropyrum caiuimm, 

 Arrlieaatheruin, aoenaceum, Lolmm pereiwie. 



