MESOZOIC COCKROACHES. -143 



The Lnternoraedian occupies a very similar belt on the inner bide, extending- nearly or 

 quite to the tip; and between them the pinched externomedian, enlarging- a little toward 

 the tip, finds narrow quarters. The anal area is very brief, but the character of its vena- 

 tion is not known. 



Two of the species come from the English Purbeeks; the third from the German 

 Lias. 



Ctenoblattina arcta sp. now 



PI. 46, figs. 1, 2. 



This minute species, as may be seen by fig". 2, has its venation somewhat obscured, 

 partially perhaps by the thickness of the integument. In its interpretation, in fig. 1, it 

 is probable that the internomedian area is given too little width, as its apical nervules are 

 given to > little curvature. The form of fig. 2 is more correct. The wing is broadest at 

 the extremity of the anal area, just before the end of the basal third; up to this point it 

 increases rapidly in size, the humeral angle being strongly docked, and beyond tapers 

 very gently to a well rounded tip. The costal area (as the united mediastinal and scap- 

 ular areas may be termed) is crowded with nervules, every alternate one appearing a 

 little heavier than the others, so that the intermediate are probably intercalary veins, 

 as one would judge also from their absence from the internomedian area, where the 

 veins are more distant. Excepting for the simple division in the middle of the basal half 

 of the wing, the externomedian vein does not fork before the middle of the wing, and 

 then but narrowly, but the whole of this region is obscure, though it seems certain that 

 it occupies outwardly nearly the whole tip of the wing. The anal furrow is distinct and 

 very strongly arcuate. The anal area is neither elevated nor depressed, the whole wing 

 being entirely flat. The wing is about 2.7 times longer than broad, its length being 5.5 

 mm. and its greatest breadth a little more than 2 mm. 



The specimen comes from the English Purbeeks (precise locality not known), and 

 occurs on a stone of a very pale sordid brown color, on which the veins appear dark 

 brown; it was received from Rev. P. B. Brodie. 



On account of the obscurity of the venation, and its apparent derivation from the 

 thickness of the integument, I formerly, from partial study, considered this a species of 

 Heer's genus Legnophora, from the Trias, and so referred it, without name, in Zittel's 

 Handbuch der Palaontologie (II, 7GG) ; but a severer examination has enabled me to 

 trace the neuration, which cannot be made to accord with that of Legnophora. 



Ctenoblattina Langfeldti. 



Blattina Langfeldti E. Gien., Zeitschr. deutsch. geol. Gesellsch., 1880, 521, PI. 22, fig. 



3; ibid., 1884, 571. 



This species seems certainly to fall here, but Geinitz appears to have confounded the 

 costal and inner margins. The externomedian vein resembles the foregoing more than 

 the following species, but first forks much farther from the bast-. The wing is ~).7> mm. 

 long and about 2.2 mm. broad. It comes from the Lias of Dobbertin, German v. 



