MORGAN HEBARD 6l 



ISCHNOPTERA Burmcister 

 1838. Ischnoptera Burnieister. Handh. Ent., ii, abth. ii, pt. I, p. 500. 



The genus was based on four species, three at that time described, 

 the fourth doubtfully included. 



We have restricted the genus to the forms showing the features 

 given below, which we are able to ascertain from a specimen of 

 the type species before us; other species, which have been gen- 

 erally referred to Ischnoptera, but which do not agree in \-arious 

 characters here given, are properly referable to other distinct, 

 though closely related genera. 



Genotype: I[schuoptcra] morio Burmeister, selected by Kirby 

 in 1904." 



Generic Description. — Head elongate; ocelli distinct, with flat 

 surfaces of ocellar areas forming a rather sharp angle with the 

 interocellar space. '^'^ Pronotum weakly convex, becoming strongly 

 so narrowly laterad ; disk in males with two distinct sulcations 

 mesad which converge caudad, in females showing reduction in 

 organs of flight these sulci are usually obsolete; lateral margins of 

 pronotum fully as chitinous as the disk; caudal margin of pro- 

 notum very weakly and broadly convex. ^^ Tegmina with discoidal 

 sectors (these including the median and ulnar veins and their 

 branches, of which the branches of the ulnar vein are the more 

 numerous) weakly radiating so that the branches near the sutural 

 margin are weakly oblique to that margin (PI. II, fig. 10). Wings 

 with area between discoidal xem and anterior margin narrow 

 throughout; mediastine vein extending more than half the dis- 

 tance to the apex of the wing, from which spring a number of the 

 costal veins; none of the costal \eins enlarged distad; discoidal 

 vein percurrent to apex of wing, undivided, with a number of dis- 

 tinct, well spaced, nearly perpendicular veinlets connecting with 



" Synon.- Cat. Orth., i, y,. 80. 



*" In females showing greatly reduced tegmina, the head shows decidedly less speciali- 

 zation, and, as a result, the ocellar areas are very weakly defined and the ocelli represented 

 by pale spots. This condition is not peculiar to the genus; throughout the Blattidae it is 

 found coincident with very decided reduction in the organs of flight and an accompanying 

 greater truncation of the caudal margin of the pronotum. 



*' The caudal margin of the pronotum becomes more truncate and more nearly trans- 

 verse in material showing decided reduction in the organs of flight. See footnote 80. 



MEM. AM. ENT. SOC, 2. 



