404 SAMUEL H. SCUDDER ON 



2. Promylacris ovalis. 



PI. 31, figs. 1-4. 



Promylacris ovale Scudd., Proc. Acad. ]S"at. Sc. Philad., 1885, 34-45. 



This species is represented by a single specimen and its reverse, in a nodule preserv- 

 ing well the front half or more of the body. 



The wings have all the tip removed, but the curve of the costal margin is so strong 

 that we may believe only a little less than a third to be gone. This would give to the 

 whole body a rather short obovate form. The front wings have a strongly develoijcd 

 humeral lobe, and a costal margin of considerable convexity; the inner margin appears to 

 be sti-aight but is ill defined. The mediastinal vein originates at the middle of the base of 

 the wing, and after the basal curve the innermost vein runs in a straight course to near 

 the end of the fragment, or to what is apparently near the middle of the wing; most of the 

 branches dichotomize. The scapular vein runs, beyond the base, in a nearly straight 

 course constantly approaching the margin and terminates appai'cntly at the middle of 

 the apical half of the wing; it has three principal branches each of which has several 

 superior branchlets. The externomedian vein is far more important, occupying with 

 luimerous branches the entire apex of the Aving; the principal branches are three, all 

 of which originate near together far toward the base and dichotomize beyond. The in- 

 ternomedian area is unusually small, reaching apparently not so far toward the tip as the 

 scapular. The anal area is considerably domed, the furrow very deep, considerably 

 ci;rved and ending only a little beyond the basal third of the wing; the veins are numer- 

 ous, simple, parallel, curved. 



Besides the wings, the prothoracic shield and the legs maybe seen; the former isreg- 

 idarly arched, about a foui'th as high as broad, and twice as broad as long; the latter 

 are seen but vaguely as discolorations through the wings, but closely resemble those of 

 modern cockroaches; whether they are spined or not cannot be said. 



Length of fragment of wing, 20 mm.; estimated entire length, 29 mm.; breadth of 

 same, 12 mm.; length of prothoracic shield, 8.5 mm.; breadth of same, 15.5 mm.; length 

 of hind femora (partly estimated), 7 mm.; breadth of same, 1.5 mm. 



The single specimen comes from Mazon Creek, 111., and was sent to me by Mr. W. 

 F. E. Gurley of Danville, 111. 



3. Promylacris rigida sp. nov. 

 PI. 31, fig. 6. 



A single specimen of which the anterior half is well preserved, including most of the 

 prothoracic shield; but the apical half of the tegmina is broken aAvay, revealing the 

 apical parts of the hind wings somewhat displaced. It is of about the size of P. ovalis and 

 resembles it more than it does the other species, but has its prothoracic shield much 

 narrower in proportion to its length, being distinctly less than half as broad again as 

 long, the front margin distinctly though bluntly angulated in the middle, smooth througli- 

 out, very gently and uniformly arched and overlapping the wings posterioi'ly. 



