58 S. H. SCUDDER OX PALAEOZOIC COCKROACHES. 



is similar, being subtriangular, tapering anteriorly, but with rounded sides and a rounded 

 front. The abdomen in the single species where it occurs is extraordinarily slender, but 

 apparently not cylindrical, as would at first appear from Goldenberg's illustration. 



This genus differs from Archiinylacris in the greater conformity of the mediastinal and 

 scapular areas, the superior position of the branches of the externomedian vein, and the 

 usually smaller extent of the scapular area; from Anthracoblattina, Gerablattina, and 

 Hermatoblattina by the greater brevity of the mediastinal area and the correlated greater 

 importance of the scapular area, as well as from the former by the superior position of the 

 veins of the externomedian vein, and from the latter by the superior position of the 

 branches of the scapular vein ; from Progonoblattina it is readily separable by the unim- 

 portance of the externomedian area; Oryctoblattina differs from it in its excessive and 

 peculiar development of the mediastinal area with its inferior branches, and by the exces- 

 sive narrowness and length of the mediastinal area, as well indeed as by nearly every 

 other feature in the wing ; while Petrablattina, with the extraordinary development of its 

 externomedian area, formed of longitudinally directed but yet superior branches, can be 

 confounded with no other. 



This genus is by far the most numerous in species of all the carboniferous types, a third 

 of the species belonging to it ; it is, however, almost exclusively European, for only two 

 American species fall into it, one of these the first described from America ; this is not a 

 little curious, for the first known fossil cockroaches of the European coal measures also fall 

 into this genus. 



Etoblattina primaeva. PI. 3, fig. 7. 



Blattina jjrimaeva Gold.. Sitzungsb. math-nat. CI. k. akad. Wiss. Wien, ix, 38; — lb., Pa- 

 laeontogr., iv, 22, taf. 3, fig. 4 ; — lb., Foss. Ins. Saarbr., 6, taf. 1, fig. 4 ; — lb., Jahresb. 

 Gymn. Saarbr., 16; — lb., Faun, saraep. foss., i, 16, taf. 2, fig. 13; — lb., Faun, saraep. 

 foss., ii, 19, 51 ; — Gieb., Ins. Vorw., 31G ; — Bronn, Leth. Geogn., 3 aufl., I, ii, 683, 

 tab. 9 3 , fig. 15 a ; — Heer, Viertelj. naturf. Gesellsch. Zurich, ix, 288 ; — Roem., Leth. 

 geogn., tab. 47, fig. 18 ; — Gein., Geol. Steink. Deutschl., 149. 



The front wing has a very regular ovate form, and is broader in proportion to its length 

 than any other species of Blattina, being only twice as long as broad ; beyond the expand- 

 ing base, the front margin is very gently convex, and the hind border, at first nearly 

 straight, tapers considerably in the apical half; the apex is very broadly rounded. The 

 veins originate in the middle of the wing, but all curve at first ivpward, and where the 

 middle ones assume a general longitudinal direction, the externomedian is considerably 

 above the middle. The mediastinal vein passes with a very slightly sinuate course to a 

 short distance beyond the middle of the front margin, emitting five or more simple or 

 simply forked oblique branches. Beyond the basal curve, the main stems of the scapular, 

 externo- and internomedian veins are longitudinal, nearly straight, and parallel ; the first 

 terminates in the upper and the last in the lower part of the tip, leaving only the central 

 part of the apical margin in the possession of the externomedian vein. The scapular vein 

 branches from its base and emits about five branches which are generally simply forked, 

 and the last of which runs parallel to the extremity of the main stem. The externomedian 

 is forked before the middle of the wing, its branches approximate and simply or doubly 



