1885.] NATURAL SCIENCES OF PHILADELPHIA. 107 



the middle of the outer half of the costal border, and is furnished 

 with simple, straight, oblique branches, not so numerous as in the 

 other species, to judge by the figure, though they are spoken of 

 by Geinitz as " very numerous and closely crowded." Just before 

 the scapular reaches the tip of the mediastinal, it turns parallel 

 to the costal margin, runs to the upper tip of the wing, and emits 

 branches similar to those of the mediastinal, but of course of 

 equal length. All the externomedian branches run almost longi- 

 tudinally, are straight, sometimes forked, and appear from the 

 figure to be less crowded than the mediastinal branches, though 

 they are compared by Geinitz to the barbs of a feather. The 

 internomedian runs to just beyond the broadest part of the wing, 

 being thus longer than the mediastinal, and sends less crowded, 

 gently curved, usually forked, rather short branches to the border. 

 The few anal branches curve and strike the inner margin. Length, 

 5 mm.; breadth about 2*25 mm. 



From the Lias of Dobbertin, Germany. The description is 



drawn up from the data given by Geinitz. 

 i 

 Pterinoblattina intermixta, sp. nov. 



A nearly complete wing of this species has almost the same 

 shape as P. chrysea, but the upper part of the apex is more pro- 

 duced. The mediastinal vein terminates before the middle of the 

 outer half of the wing, and the area narrows more gradually than 

 in any of the others ; its branches are gently curved, and often 

 forked, but not excessively crowded. Just before reaching the 

 tip of the mediastinal, the scapular vein suddenly bends toward 

 the apex, running subparallel to, but away from the costal margin, 

 terminating at the tip and emitting a crowd of curved and forked 

 branches. The closely crowded externomedian branches part at 

 an angle of 45° with the stem, are straight, and fork only just 

 before the tip, forming a tolerably regular belt of crowded vein- 

 lets along the margin. The basal branches, however, are inter- 

 fered with and affected by the internomedian vein, which is nearly 

 straight, at first running plump against the externomedian 

 branches, curves then downward parallel to these and terminates 

 a little before the mediastinal ; it is furnished abundantly with 

 branches curving like its extremitj^ and branching next the border 

 like the externomedian branches, but where it abuts against these 

 latter they simulate the appearance of the internomedian branches 

 so as to appear as if a part of the internomedian area, and thus 



