NO. 1530. THE DECTICINJE OF NORTH AMERICA— CAVDELL. 389 



blance of stout spines. B^lytra, except in (jilleftei, where they are 

 abortive, the only known .specimen probably immature, overlapping- 

 above in both sexes and projecting be3ond the pronotum about half its 

 length in the male; somewhat less in the female; wings are about the 

 same size as the elytra and coal black. Legs stout and moderately 

 long, the posterior femora less than two times as long as the prono- 

 tum or considerabh' more, or much more, than two times as long, 

 moderately or little swollen in the basal half and unarmed beneath or 

 armed on both carinie with a few very small blunt spinules; anterior 

 til)i{v armed ajjove on the outer side only with three or four spines, 

 rarely with but two. Abdomen moderateh' heavy; supraanal plate 

 elongate triangular, partially hidden beneath the last abdominal seg- 

 ment, which, in the male, extends backward as two projections, tri- 

 angular, about as long as the basal width, the intervening sinus 

 V-shaped; last abdominal segment of the female simple but more 

 depressed and shorter than that of the male; subgenital plate of both 

 sexes apically forked, the incision V-shaped, the terminal styles in the 

 male very short and stout, subtriangular or cylindrical and more elon- 

 gate. Cerci short, scarcely attaining the apex of the subgenital plate 

 in the male (tig. 75), cylindrical in both sexes, in the female simple, 

 conical; in the male tapering, blunth^ rounded at the apex and fur- 

 nished on the inner side with two short, round, blunt teeth, one just 

 before the apex and one just beyond the middle. Ovipositor consider- 

 ably longer than the posterior femora and distinctly curved downward. 



Tyjpe. — Plagiostira alhonoiata Scudder. 



The members of this genus may be separated as follows: 



KEY TO THE SPECIES OF PLAC4IOSTIRA. 



A. Pronotal disk distinctly more than one and one-half times as long as its greatest 

 width, the lateral carime parallel or scarcely perceptibly l;)owed outward, the 

 disk rectangular. Organs of flight projecting well beyond the ])ronotum. 

 B. Posterior femora more than two times as long as the pronotum, 



albonotat((, p. 389. 

 B'. Posterior femora less than two times as long as the pronotum, 



(dhonotata var. hrevipes, p. 392. 



A^. Pronotal disk no more than one and one-half times as long as the greatest 



width, the lateral carin;e distinctly bowed outward in the middle, the disk 



subovate. Organs of flight not projecting beyond the pronotum, at least in 



the only specimen seen gilletiei, p. 392. 



PLAGIOSTIRA ALBONOTATA Scudder. 



Plagiostira alhonoiahi Scudder, Ann. Rept. Chief Eng., 1876, p. 501 (1876) ; Ann. 

 Rept. U. S. Geol. Surv. W. 100 Mer., 1876, p. 281; Can. Ent, XXVI, 1904, 

 p. 182; Cat. Orth. U. S., 1900, p. 79 — Scudder and Cockerell, Proc. Davenp. 

 Acad. Nat. Sci., IX, 1902, p. 55— Oaudell, Proc. U. S. Nat. Mus., XXVI, 

 1903, p. 807.— KiRBY, Syn. Cat. Orth., II, 1906, p. 195. 



