1885.] NATURAL SCIENCES OF PHILADELPHIA. 35 



broad as long. The front wings have a strongly developed 

 humeral lobe and a costal margin of considerable convexity. 

 The mediastinal branches are clustered into three groups ; the 

 scapular vein is composed of only two branches, each of which 

 forks with slight divarication ; the externomedian vein has three 

 principal branches, all of which originate far toward the base of 

 the wing ; the internomedian area is unusually small, apparently 

 not reaching so far out as the scapular area. The fragment is 20 

 mm. long and the wing 12 mm. broad, but it was probably about 

 29 mm. long. 



Carboniferous deposits of Mazon Creek, 111. Received from 

 Mr. Wm. Gurley. 



PAKOMYLACEIS (-apo s , //uWpfj), nov. gen. 

 The mediastinal vein consists of at least seven or eight prin- 

 cipal bi*anches, several of them forking close to the base, the 

 outermost extending far toward the tip of the wing, making this 

 area unusually important ; the scapular is also important, the 

 main vein running through the middle of the wing in a straight 

 course to the tip ; the externomedian branches do not separate 

 widely, and occupy on the margin of the wing only the lower 

 half of the broad apex ; the anal furrow is deeply impressed, and 

 strikes the middle of the inner margin. 



Paromylacris rotundum, nov. sp. 



The single specimen shows the larger portion of the upper 

 surface, and all the more important parts, visible from above. 

 The whole body is strongly arched, and the central portion of 

 the pronotal shield, which is twice as broad as long, is elevated 

 about 4\ r ) mm. above the margins. The front wings are obovate, 

 scarcety narrower at tip than at base, barely twice as long as 

 broad ; the humeral angle very prominent. The scapular vein 

 has four or five straight superior branches ; the externomedian 

 vein runs parallel to the scapular, and has two dichotomizing 

 branches. The length of the wing is 29 - 5 mm., and its width 

 15 mm. 



Carboniferous deposits of Mazon Creek, 111. Mr. R. D. Lacoe, 

 No. 2026. 



SPILOBLATTINA (<xz:\os, Blattina) nov. sp. 



This genus is allied to Etoblattina, but differs from it and from 

 all other genera of Blattinariae in the divergence of the scap- 



