S. H. SCUDDER ON PALAEOZOIC COCKROACHES. 75 



Etoblattina didyma. PI. 2, fig. 13. 



" Dictyopteris didyma Rost, Dissert, flor. Wettin, 21." 



Blattina didyma Germ., Miinst. Beitr. z. Petref., v, 92, tab. 13, fig. l a l b ; — lb., Yerst. 

 Steink. Wettin, vii, S3, tub. 31, figs. 2, 3;— Quenst., Handb. Petref., tab. 24, fig. 16 ; — 

 Gieb., Deutschl. Petref., 637 ; — lb., Insr Vorw., 314; — Pict., Traite Pal, 2" eU, n, 

 362, pi- 40, fig. 2 ;' — Heer, Viertelj. naturf. Gesellsch. Zurich, ix, 287 ; — lb., Faun. 

 saraep. foss., ii. 19. 



Not Blattina '.' didyma Germ., Verst. Steink. Wettin, vii. 87, pi. 31, fig. 10 ; nor HI. didyma 

 Gein., Neues Jabrb. f. Mineral.; nor Blatta didyma Germ. - Ber., Org. Eeste Bernst., 

 a, 34-35. 



Compare the synonomy of Anthracobl. sojAta. 



The front wing is long anil nearly equal, the eostal margin regularly and considerably 

 convex, the inner margin almost straight until near the tip, the apex broadly and regularly 

 rounded. The veins appear to originate somewhat above the middle of the base, but about 

 the middle line of the wing. The mediastinal vein runs parallel to the costal margin at 

 about the middle of the anterior half of the wing, and terminates by a somewhat rapid 

 curve upward at about the middle of the apical half of the wing; it emits a large num- 

 ber of not very closely crowded simple or forked oblique branches. The scapular vein, 

 beyond its basal curve, has a nearly longitudinal course, but apically bends upward some- 

 what abruptly, 3 and terminates just before the tip of the wing; it first divides at about the 

 end of the basal third of the wing; its first branch is compound, but the others, two or 

 three in number, 2 are simple ; the vein is very distant from the mediastinal, so that the 

 area, at its widest, occupies nearly one-half the breadth of the wing. The externomedian 

 vein also divides early, before the middle of the wing, and occupies with its branches the 

 entire broad apex of the wing, and encroaches slightly on the inner margin; it emits first 

 a compound arborescent branch, and then several simple branches, the latter terminating 

 below the extreme apex. The internomedian vein, beyond its basal curve, is nearly 

 straight, and terminates a little before the apex of the wing, emitting eight or nine simple 

 or occasionally forked, somewhat sinuous, oblique branches, besides, in the only example 

 known, a single superior branch parallel to the main vein. 3 The anal furrow is well im- 

 pressed, strongly oblique, and terminates at the end of the basal third of the wing; the 

 numerous anal veins which follow it are similarly but more gently curved and simple or 

 forked. 



The wing figured by Germar is a little broken at the base, but otherwise nearly perfect, 

 for although the apical margin is represented as doubtful by Germar, its agreement with 

 the tips of the veins renders it almost certainly correct; the wing thus preserved is 40 mm. 



1 This i> the way it is represented in Germar's larger and main internomedian vein beyond tin- origin of this superior 



presumably more correct figure in his Wettin fossils; in his bninch is very regular, while in all those species in which 



smaller figure it lias no such abrupt 1" nd. the internomedian vein changes from an oblique to a longi- 



'- Different in the several figures by Germar. tudinal course ami is accompanied by an arborescent disposi- 



3 It is impossible, from Germar's figures, to lie quite sure tion of the apical branches, this portion of the area is either 



that the lowest tw.. in- three branches of the extern, .median itself Idled with similar arborescent branches, or is at least 



vein do nut belong to this superior branch of the interno- irregular. In his description Germar also assigns these 



median vein, which latter would then have the peculiar dis- doubtful branches i<> tie externomedian ami nol to the in- 



position comi i to Etobl. anaglyptica and other allied ten ledian vein, and we may therefore reasonably follow 



forms; but the mode of distribution of the branches of the the same course. 



