30 



branches only towards the costa, except in Ectobia, where such are 

 also emitted on the opposite side. The inframedial or ulnary vein 

 is only separated by a very narrow space at the base from the 

 preceding, which gradually widens during its subsequent course; 

 it mostly separates into an anterior and posterior branch from 

 the start, both branching out towards the border, the inter 

 space being more or less crossed by transverse veinlets. The 

 difiding or anal vein is the last ; it proceeds in a more or less 

 pronounced, generically distinct, curve (often very short), and is 

 unbranched. By it the anal area is bounded, which contains a 

 varying number of straight or reticulating veinlets. The left 

 elytron usually covers the right one, but in rare cases have I 

 observed the reverse. These organs afford most important dis- 

 tinctive characters by the arrangement, curvature, tfec, of the 

 veins for the separation of families and genera, and it is the 

 neglect of these which renders the descriptions by Walker and 

 some others so unsatisfactory. 



The Wings present homonymous veins, but present a different 

 arrangement in respect of the areas bounded by them, the anal 

 vein being straight, dividing the wing nearly in equal halves, and 

 terminating in an angular emargination of the exterior margin, 

 or in some genera cut off by a triangular area, which folds fan- 

 like, and in some cases is more or less largely produced beyond 

 the ordinary outline of the border. The costal vein turns usually 

 midway towards the fore margin, emitting some straight branches 

 into the same. The scapulary vein emits oblique branchlets into 

 the apical half of the costa, and a stouter branch from about the 

 middle towards the apex. In some genera, as Ectohia and 

 Phyllodromia, it is also connected by short transverse vein with 

 a spurious one proceeding from the border towards the middle 

 without a terminal connection. The ulnary (inframedial) vein 

 is mostly separated by a narrow hyaline space from the foregoing, 

 and usually emits more or less numerous branchlets rearward, but 

 in some cases, as in Ectobia and Phyllodromia, remains simple. 

 The anal area contains a number of nearly straight radiating 

 veinlets, more or less connected by transverse reticulations. Im- 

 portant distinctions are often supplied by the wings. 



The venation of rudimentary or abbreviated organs of flight is 

 mostly quite distinct in both pairs, and the border is either entire 

 (Periplaneta) or jagged (Panesthia australisj. When lobiform, 

 the bases only of the principal veins are more or less discernible. 

 The presence of either of these forms, when free, denotes adults; 

 while in the advanced larval stage, and preceding the final moult, 

 both pairs (or one) are made manifest by elongation of the hind- 

 angles of the meso- and meta-notum, and their being more or less 

 plainly discernible, although covered over completely by a thin 



