1885.] NATURAL SCIENCES OP PHILADELPHIA. 109 



tance, and in the large anal area the veinlets terminate on the 

 margin ; the anal furrow is strongly arcuate, and deeply impressed. 



Neorthroblattina albolineata, sp. nov. 



The single wing has lost the tip, but all the essential features are 

 preserved, excepting the form of the tip. The wing is very dark 

 colored, and the veins appear as very pale lines upon it. The 

 costal margin is gently and equably arched, while the inner margin 

 is perfectly straight. The externomedian vein is little developed, 

 first forking and then not widely in the middle of the wing, its 

 fuller development being prevented by the ample and unrestricted 

 development of the internomedian vein, which runs in a full 

 rounded course nearly to the tip of the wing. The anal area is 

 interesting because the veins of the upper half run close to, but 

 do not impinge upon the anal furrow, curving downward just before 

 reaching it, and either running into the next vein below and ter- 

 minating there, or continuing parallel to the furrow and termi- 

 nating on the inner border. Length of fragment, T mm. ; probable 

 length of wing, 9 mm. ; breadth of wing, 3*5 mm. 



Triassic beds near Fairplay, Coloradg. 



Neorthroblattina Lakesii, sp. nov. 



Several specimens of this species were found. The costal 

 margin is arched as in the last species, and the inner margin has 

 an almost equal opposite curvature. The externomedian vein has 

 a very sinuous course, and forks before the middle of the wing 

 with abundant neuration, occupying on the margin the entire tip 

 of the wing, and almost the outer half of the lower margin, while 

 the internomedian is reduced to an arching vein, extending but 

 little beyond the anal furrow, and with onty two or three branches ; 

 the anal veins are all parallel to the anal furrow and simple. Length 

 of wing, 9 mm.; breadth, 3*5 mm. 



Triassic beds near Fairpla}', Colorado. This species is named 

 after Prof. Arthur Lakes, of the School of Mines, in Golden, 

 Colorado, who first made known these beds ; this species being 

 one of the first discovered by him. 



Neorthroblattina rotundata, sp. nov. 



The costal margin in this species is very strongly arched, while 

 the inner margin is straight, giving a very different aspect to the 

 wing. It closely resembles the preceding species in the mediastino- 



