408 SAMUEL H. SCUDDER ON 



nodule 60 x 45 mm. iu size, found in the carboniferous beds of Mazon Creek, Grundy 

 Co., Illinois. 



Paromylacris ampla sp. nov. 

 PI. 31, fig. 7. 



The single specimen known is of large size and tolerably well preserved, showing the pro- 

 thorax (imperfectly), most of the fore wings, and an unimportant partof the hind wings. 

 The body is not so strongly vaulted as in the preceding species, but is considerably more 

 arched than most modern cockroaches. The prothorax is not Avholly exposed, being part- 

 ly still imbedded in the rock (upon the right side of the figure), but it is apparently not 

 quite twice as broad as long and so diflers conspicuously from the other species ; a triangu- 

 lar space in the posterior middle of the disk is flattened and more or less rugose, while 

 the rest is smooth ; there is no sign of margination. In the wings, however, the vaulted 

 area tei-minates just before the costal edge, leaving a slight horizontal marginal shelf free 

 of arcuation. 



The fore wings are a little more than twice as long as broad, the costal area well but 

 not strongly arcuate with a decided humeral angle. The mediastinal area is large, occu- 

 pying just about one-fourth of the wing, triangular, broad at base, tapering to the tip 

 which is well beyond the middle of the wing; the proximal veins of this area are single, 

 the middle ones deeply and widely forked and the distal third or more is occupied by a 

 compoundly forked vein, all of these radiating with a faint arcuation. The scapular vein 

 is sharply curved at base and beyond runs nearly straight through the middle of the wing 

 and must terminate at or even below the tip; its branches, four or five in number, ai-e 

 either singly forked somewhat beyond their middle or are simple and all are subparallel 

 to the innermost course of the mediastinal vein. The externomedian and internomedian 

 veins have little space wherein to develop and each is simple and single in its basal half 

 and nearly straight except for the necessary basal curve; probably in their outer half they 

 occupy about equal space. The anal furrow is very deep and sharp, and the anal area 

 strongly vaulted, especially in the neighborhood of the former, which is very strongly 

 rounded, nearly bent at base and beyond this at first straight, then gently arcuate, termi- 

 nating apparently well beyond the middle of the wing; the anal veins, overlooked by the 

 artist, are vei-y numerous, parallel, arcuate, simple, nearly tAvice as close as the veins of 

 the wing generally. 



Parts of the hind wing are also seen beyond the broken fore wings, but show only a 

 multitiide of nearly parallel and straight, simple or forked veins. 



This species differs from the preceding in its more oval contour, tapering much more 

 at both ends, the less vaulted form, the longer and narrower thorax, and the simpler and 

 weaker construction of the externo- and internomedian veins. 



Length of fragment, the hind wing a little thrust beyond its natural position, 45 mm.; 

 probable length, 42 mm. ; length of prothorax, 12 mm. ; breadth of same, at least 21 mm. ; 

 length of fore wing, 31 mm. ; breadth of same, 14 mm. 



One specimen, Mazon Creek, 111. Eeceived from Mr. R. D. Lacoc under the number 

 2088ab. 



