CARBONIFEROUS COCKROACHES. 403 



TABLE OF THE SPECIES OF PROMYLACRIS. 



Prothorax distinctly twice as broad as long. Scapular vein much more important than the externomedian 



1. P. testudo. 

 Prothorax distinctly less than twice as broail as long. Scipular vein not mire important than the externomedian. 

 Protliorax more than lialf as broad again as long. Scapular vein far less important than tlie externomedian ; anal 



veins simple 2. P. ovalis. 



Prothorax less than half as broad again as long. Scapular vein not far less important than the externomedian ; 

 aual veins mostly forked 3. P. rigida. 



1. Promylacris testudo sp. nov. 

 PI. 32, fig. 6. 



A single excellently preserved s]iecimen showing both obverse and reverse, slightly 

 broken on one side. The form of the body with closed wings is sHghtly more elongate 

 tlian in P. ovalis and it is a smaller species. 



The front wings have a strongly developed well rounded humeral lobe; the costal 

 margin is strongly and regularly convex, while the inner mai-gin is nearly straight, and 

 the apex, so far as can be told, well i-onnded and not at all produced. The mediastinal 

 area, which is very broad at base, rapidly narrows and terminates at some distance be- 

 fore the middle of the wing and before the anal furrow; the main vein is sinuous in its 

 course, and several of the radiating branches arise from the main stem and nearly all are 

 forked near the margin. The scapular vein, strongly arcuate at the base, is nearly straight 

 but apieally arcuate in the opposite sense, running in the middle subparallel to the cos- 

 tal margin, terminating just before the tip of the wing; half a dozen more or less forked 

 branches originate from it mostl}^ in the middle third of the wing, neighl^oring ones 

 sometimes amalgamated at their bases into a bunch. The externomedian branches oc- 

 cupy all but the upper portion of the tip of the wing, but they are not numerous, though 

 the earliest originate as far or nearly as far as the scapular branches. The internome- 

 dian area apparently occupies about half the space from the anal furrow to the tip of the 

 wing, but the veins are few and obscure. The anal furrow is very deeply impressed, 

 the anal area being strongly vaulted, its veins delicate, numerous, straight and paral- 

 lel; the furrow terminates a little bej'ond the middle of the wing. 



The whole body is considerably arched but the outer fourth of the costal region from 

 the scapular vein to the margin is flattened, a flattening which is shared in no way by 

 the transverse pronotum; the latter is slightly more than twice as broad as long with 

 well arched, slightly appressed front, pronounced though rounded posterior lateral an- 

 gles, scarcely convex hind margin, and minutely marginate edge; a slight median furrow 

 is indicated, besides two anteriorly converging but distant straight and faint depressions 

 of the surface, and a scarcely perceptible similar V-shaped central impi'cssion. 



Length of whole body, 23 mm.; of pronotum, 4.75 mm.; width of same, 10.5 mm.; 

 length of wing, 19 mm.; breadth, 8 mm.; breadth of closed wings, 14 mm. 



The single specimen known comes from Mazon Creek, 111., and was received for ex- 

 amination from Dr. J. S. Newberry. It is preserved in the Columbia School of Mines. 



