S. H. SCUDDER OX PALAEOZOIC COCKROACHES. 71 



of the wing. The scapular vein runs subparallel to the costal border and rather distant 

 from it. but 'Iocs not have a regular curve, for it divides not far from the end of the basal 

 third of the wing, and turns from the original course as much as does the branch; it 

 appears, therefore, to he formed of two stems, and each of these emits in a similar 

 manner three branches, the first two forked, the last simple,' the distribution of the 

 branches of this vein is therefore arborescent, the veinlets being mainly longitudinal, and 

 together occupying all the space beyond the mediastinal vein almost, if not quite, to the 

 tip. The externomedian vein has a broadly arcuate course, the apical portion of which is 

 nearly straight ; it begins to divide near the middle of the wing, opposite the secondary 

 forking of the scapular vein, and emits four straight longitudinal branches, which, if they 

 fork at all, only do so next the apical margin; they occupy a very slender field on the 

 apical margin, apparently more below than above the very apex. The internomedian fol- 

 lows closely the course of the externomedian vein, being nearly straight in its apical half, 

 and terminates shortly before the tip of the wing, emitting eight or nine long, arcuate, gen- 

 erally simple, occasionally forked branches, the apical ones more longitudinally disposed 

 than the others, and all tolerably close. The anal furrow is strongly arcuate, and strikes 

 the inner margin certainly before the middle of the wing, perhaps considerably before it ; 

 the few anal veins that can be seen appear to show that they are not very numerous and 

 are arcuate next the anal furrow. 



The wing is of a tolerably large size, the length of the fragment being 24.-3 mm., the 

 probable length of the wing from 28-30 mm., and the breadth of the fragment doubtless 

 that of the whole wing. 12.75 mm. ; the breadth to the length being about as 1 I 2.27. 

 The upper surface of the wing is exposed, and is flat and admirably preserved ; the veins 

 at the base of the wing with their branches, as far as the forking of the scapular, are 

 slightly raised ; beyond this point, the principal veins, although elevated, are sulcate, and 

 the branches of the mediastinal, scapular, and externomedian are feebly impressed, while 

 those of the internomedian vein are slightly elevated ; the anal furrow, in the part lying 

 parallel to the first internomedian vein (the only part preserved), is impressed in its basal 

 half, elevated in its apical half, and then indistinguishable in character from the first inter- 

 nomedian branch, excepting in being a little less sharply elevated and slightly broader ; 

 the cross veins are equally distinct or nearly so throughout the wing, and are slightly ele- 

 vated, making a delicate tracery over the wings just indistinguishable by the naked eye ; 

 in the apical half of the wing they are nearly all straight and regularly transverse, but in 

 the basal half, and especially in the central region of the wing, they are more sinuous and 

 interlacing; this is especially true in the mediastino-scapular interspace, between the first 

 and second branches of the scapular vein, and on either side of the externomedian vein 

 where it first divides. 



Although figured by Lesquereux nearly twenty years ago, this first known of American 

 fossil cockroaches has never before been described, the remarks in the Arkansas report being 

 only of a general nature. In the strongly curved outline of the costal margin, this species 

 resembles Etobl. anaglyptica, with which it agrees also in the general distribution of the 

 areas ; it is undoubtedly more nearly related to this species than to any other, but differs 

 from it in many minor points : the veins of the mediastinal area are much more frequent 

 and crowded in Etobl. venusta; the branches of the scapular vein have a much more 

 arborescent distribution, and its first branch has as many sub-branches as the main stem. 



