1885.] NATURAL SCIENCES OF PHILADELPHIA. 37 



both the mediastinal and scapular areas, and the more rapid 

 descent to the margin of the termination of at least the former. 

 In other respects the species completely resembles S. Gardineri. 

 Two fragments only were obtained, which indicate a wing about 

 15 mm. long, and 7 mm. broad. 



Triassic beds near Fairplay, Colorado. 



Spiloblattina marginata, nov. sp. 



This species, of which only a single specimen was found, is 

 remarkable for the paucity of its neuration, and for the fact that 

 all the veins and branches are margined with a slender dark 

 edging. The scapular vein recedes more than usually from the 

 costal margin opposite the very slight median stigma, and the 

 externomedian vein is consequently more than usually curved to 

 make place for it. The probable length of the wing was 18 mm. 

 The inner margin being lost, the width can hardly be more than 

 conjectured, but it was perhaps 7 mm. 



Triassic beds near Fairplay, Colorado. 



Oryctoblattina occidua, nor. sp. 



The veins appear to originate from the middle of the upper 

 half of the base of the wing, and have scarcely the least basal 

 arcuation. The mediastinal vein runs at but slight distance from, 

 and nearly parallel to, the costal border, in the outer half con- 

 stantly but gradually approaching it, emitting numerous oblique, 

 generally simple branches ; the vein terminates in the middle of 

 the outer half of the wing, and shows no such peculiarities at its 

 tip as characterize 0. reticulata of Europe. The scapular vein 

 is also not so peculiar as there ; it runs in near proximity and 

 parallel to the mediastinal vein, but there is the same slight bend 

 in its course at the base of the principal branch ; the mass of the 

 branches, which are fewer than in 0. reticulata, do not arise as 

 there from a vein emitted abruptly from near the base of the 

 second branch, to which they are inferior, but from the principal 

 branch itself, to which they are superior. The internomedian 

 vein terminates at about the end of the middle third of the wing, 

 and has only a few branches. The externomedian branches all' 

 terminate on the inner margin. The length of the wing is 19 

 mm., its breadth 7 mm. 



Carboniferous beds of Mazon Creek, Illinois; R. D. Lacoe, No. 

 2039. 



