S. H. SCUDDER ON PALAEOZOIC COCKROACHES. 125 



ternomedian first separates itself from the others, but the other two appear to be united 

 almost throughout the basal third of the wing ; the scapular vein then turns obliquely- 

 downward in parting from the mediastinal vein at the end of the basal fourth of the wing, 

 in a direction toward the middle of the outer half of the wing; but it very soon parts 

 widely from the externomedian vein, and runs in a longitudinal, broadly arcuate course to 

 the costal margin, just before the apical eighth of the wing ; it emits three long, longitu- 

 dinal, but obliquely arcuate branches, simple or deeply forked, the first before the separa- 

 tion of the vein from the externomedian. The externomedian vein continues the direction 

 of the united scapular and externomedian veins, following closely the internomedian, and 

 terminating on the inner border, about the end of the middle fifth of the wing; it emits 

 at a wide angle about ten closely crowded, longitudinal veins, many of which fork singly or 

 doubly, nearly all of them broadly arcuate, the upper curving slightly upward, the lower 

 downward, and together embracing a very extensive area, including the entire apex of the 

 wing. The internomedian vein has a bent, arcuate course, and emits about seven long and 

 simple, sinuous, closely crowded branches, the marginal extent of this area being rather less 

 than that of the anal area. The anal furrow is distinctly impressed, pretty regularly and 

 very strongly arcuate, striking the margin at about the end of the basal third of the wing ; 

 the anal veins, nine in number, are closely crowded, arcuate, and simple. 1 



The wing is below the medium size, measuring 18.5 mm. in length and 7.5 mm. in 

 breadth ; a little of the base, however, is destroyed, which would add about 1.5 mm. to the 

 length, making it 20 mm. long, 2 and the breadth to the length as 1 : 2.6. The wing is from 

 the right side, the upper surface exposed, with a swollen anal area; from the condition of 

 its preservation, it cannot be determined whether there is any interspacial reticulation. 



Goldenberg compares this species to Etobl. anaglytica and to "Blatlina formosa Heer" 

 from the Lias, but I fail to see the slightest ground for any special comparison ; certainly 

 not with the latter ; while the peculiar basal connection of the principal veins, and, above 

 all, the distribution of the externomedian branches, forbid comparison with any palaeozoic 

 form, excepting the following species, from which it differs greatly in the multiplicity of its 

 branches and in its slenderer form. Indeed, in the crowded condition of its venation it 

 alone of all the palaeozoic cockroaches, excepting Etobl. insignis, shows any tendency to- 

 ward a thickening of the membrane of the wing, which often appears, in ancient types, to 

 have commenced by the multiplication of nervules. 



The single specimen known comes from an ironstone nodule from Lebach, above Saar- 

 louis, Germany. Dyas. 



Petrablattina sepulta. PL 6, fig. 7. 



Blattlna sejjulta Scudd., Proc. Amer. assoc. adv. sc, xxiv, b, 111, fig. 2; — lb., Can. nat, 

 [n. s.] vin, 89-90, fig. 1 ; — lb., Ins. carb. Cape Breton [p. 2] fig. 1. 



Fore wing. The wing is so fragmentary that it is impossible to say anything more of 

 the form than that the middle of the costal and inner margins are gently convex, the 

 former nearly straight. The veins would appear to have originated considerably above 

 the middle of the base. The mediastinal area occupies in the middle of the wing consid- 



1 One is incorrectly represented on our plate as forked. tion as 1 : 2.2; but his enlarged figure, presumably the most 



jives the breadth as 9 mm. and the propor- accurate, makes the breadth only 7.5. 



