MESOZOIC COCKROACHES. 4G9 



account of this curious arrangement of the veins, I proposed recently the generic name 

 here employed. The wings are very broad, expanding considerably beyond the base, 

 broadest beyond the middle, and filled with an abundance of branching veins. The 

 mediastinal, scapular and combined externomedian and internomedian veins run close 

 together, side by side, in a perfectly straight course (the shaft of the feather) from 

 near the middle of the base of the wing toward and nearly to a point on the costal 

 margin a little within the apex of the wing, and the superior mediastinal and scapular 

 and inferior externomedian and internomedian branches, crowded closely together, 

 part from this apparently common stem at nearly similar angles on either side of it; 

 while the anal area, at least where known, occupies a considerable and nearly equal 

 band along a considerable portion of the inner margin, running into and often strongly 

 interfering with the internomedian nervules. As stated in the introductory portion 

 of this paper, what was formerly regarded by me as internomedian is now looked upon 

 as unquestionably anal, so that we can only interpret the neuration by supposing the 

 externomedian and internomedian Veins to be amalgamated, and this will remove the 

 genus from the Palaeoblattariae. 



The genus was tolerably prolific in species, which vary greatly in size, the two spe- 

 cies from the middle Oolite of Solenhofen being particularly large, while one of the 

 Liassic species from Germany is one of the smallest of mesozoic cockroaches. Four 

 species (including two doubtfully referred here) are known from the middle and lower 

 Purbecks of England, two from the middle Oolite of Bavaria and three from the Lias, 

 one in Germany and two in England. 



Pterinoblattina pluma. 



PI. 48, figs. 7, 8°. 



[Without name] Westw., Quart. Journ. Geol. Soc. Lond., x, 384, 394, PI. 15, fig. IP 



(2 figs.) 

 JBlatta pluma Gieb., Ins. Vorw., 322. 

 Pterinoblattina pluma Scudd., Proc. Acad. Nat. Sc. Philad., 1885, 105-106. 



The specimen, the original of which I have had the privilege of studying, by (he favor 

 of my kind friend Rev. P. B. Brodie, is rather imperfect, and a little deceptive from the 

 fact that just that portion of the tip is missing which contains the scapular branches; it 

 is probable, however, from the longitudinal character of the apical offshoots of the me- 

 dian vein that the species more closely resembles P. chrysea than P.intermixta. There 

 is no discoloration of the stone to mark the wings, though the veins are pale; no portion 

 of any margin is preserved; it lies flat upon the stone, but the scapular vein is slightly 

 depressed while the others with their branches are slightly elevated, by which it would 

 seem that the under surface were uppermost. All the mediastinal branches are simple, 

 parallel, equidistant, almost straight, closely crowded, and part from the main stem at an 

 angle of about 45°. The median branches, the only others preserved, part at a less an- 

 gle, gradually become quite horizontal apically, are nearly as close at base as the scapu- 

 lar branches, and as most of them fork and even re-fork, though with entire irregularity, 

 become excessively crowded toward the margin. 



