S. H. SCUDDER ON PALAEOZOIC COCKROACHES. 115 



coal measures at the anticlinal next north of that in which tjie Pittston species of Lithomy- 

 lacris occur, and also on the south-east side. Lower carboniferous. 



Hermatoblattina nov. gen. (?/'/./.«, Blattina). 

 Blattina Auct. (pars). 



The two species which form this genus differ in the nature of the mediastinal area in the 

 front wings ; in one it is nearly one-third the breadth of the wing, equal nearly to the 

 extremity, and terminates close to the tip of the wing ; in the other it is fully a third the 

 breadth of the wing near the base, and diminishes regularly to the extremity, which is 

 somewhat beyond the middle of the outer half of the wing ; in both the vein is gently 

 sinuous and the branches frequent, oblique and generally simple. The scapular vein, 

 although beginning to branch before the middle of the wing, has only two or three 

 branches, which are inferior, diverge but slightly, and may or may not fork, so that the 

 area occupied by the vein is slight, and terminates at the tip of the wing. In consequence 

 of the inferior position of the branches, the equal interspace between the mediastinal and 

 scapular veins is marked by oppositely diverging branches. The externomedian vein is very 

 similar to the scapular in extent, place and mode of branching, but the branches may be 

 either superior or inferior, but always fall upon the margin below the apex of the wing. 

 The anal and internomedian areas are very broad at base, occupying more than half the 

 breadth of the wing, but narrow rapidly, the internomedian being considerably arcuate, 

 and terminating not very far from the apex ; the branches of the externomedian are as 

 oblique as those of the mediastinal area, and although very long and straight, fork very 

 little. The anal furrow is not very pronounced, more or less arcuate, and terminates not 

 far beyond the basal third of the wing ; the anal veins are subarcuate, subparallel, frequent 

 and simple. Nothing is known of the genus but front wings, which are unusually stout, 

 the breadth being contained in the length scarcely more than two and a quarter times ; 

 with the possible exception of Petrablattina, the average form is stouter than in any other 

 genus, although other genera contain stouter species. 



This genus is peculiar for the inferior position of the branches of the scapular vein, a 

 characteristic it shares only with Oryctoblattina, from which it is readily separated by the 

 slender development of the same vein, and by the different nature of almost all of the 

 others. But for the inferior position of these branches of the scapular vein, it could hardly 

 be separated from Gerablattina. From Archimylacris and Etoblattina it is distinguished by 

 the breadth and extent of the mediastinal area. From Anthracoblattina it is again 

 separated by the inferior position of the scapular branches. The limited extent of the 

 combined areas of the scapular and externomedian veins readily distinguish it from Progo- 

 noblattina, while the totally different nature of the externomedian vein in Petrablattina 

 permits of no confusion with that, 



The two species belonging here come from the old world, and are of large size. 



Hermatoblattina wemmetsweileriensis. PI. 4, fig. 14. 



Blattina wemmetsweileriensis Gold., Faun, saraep. foss., ii, 19, 24, 51, taf. 1, fig. 9. 



Fore wing. The wing is broad and nearly equal, almost imperceptibly diminishing in 

 size up to the apical fourth of the wing ;' the costal margin is very gently and regularly 



1 This scarcely appears on our plate, where the apical half of the costal margin is a trifle too full. 



