62 Mr. S. H. Scudder on Mesozuic Cockroaches. 



wings are exceedingly long and slender, particularly in B. 

 symyriis, Westw. (which may be taken as the type), with 

 nearly or quite parallel sides. The mediastinal vein termi- 

 nates not far from the middle of the wing, and sends out a 

 multitude of crowded offshoots to the margin. The scapular 

 vein unites in the basal third of the wing with the externo- 

 median, and throws off rather distant oblique veins, first to 

 the mediastinal and afterwards to the border. The externo- 

 median and internomedian veins have together several more 

 or less forked very longitudinal branches, all of which appear 

 to terminate on the apical margin, while the main anal vein, 

 longitudinally oblique, extends nearly as far as the medias- 

 tinal, and the outer half of the inner margin of the wing 

 seems to have no veins falling upon it ; the veins of the anal 

 area run obliquely from the margin upward and outward to 

 the main anal vein. 



As to the genera of Giebel, six species are placed by him 

 in Rithma^ two in EUsama, and one in Nethania. The 

 species of Nethania is rather too uncertainly figured to deter- 

 mine by the illustration alone where it belongs. The two 

 species of 



Eltsama 



figui'ed by Brodie certainly belong together, and seem to con- 

 stitute a natural genus. By the kindness of the Rev. Mr. 

 Brodie I have seen the original of his pi. v. fig. 1 [Elisama 

 Kneri of Giebel) and another specimen which seems to belong 

 to E. minor, so that I can more fully characterize this genus. 

 The mediastinal and scapular veins appear here to constitute 

 one vein, and to occupy almost the entire upper half of the 

 wing. The externomedian and internomedian veins fill the 

 lower half between them with parallel veins, which at their 

 origin curve at once strongly downward, and then run longi- 

 tudinally to the apical margin, leaving only the meagrest 

 possible space to the anal area, which is indeed broken off 

 from the two specimens I have seen, and does not appear in 

 the figures published by Brodie. In addition, in both the 

 species there is an abundant but imperfect cross-venation at 

 the base of the externomedian and internomedian areas, and 

 on the latter a large discoloured spot, which may of course be 

 confined to these U\o species only. 



RiTHMA 



contains more incongruous material. I have myself recog- 

 nized in the English species I have examined autoptically 

 only one of the species referred to it, named R. Murchiaoni 



