126 S. H. SCUDDER ON PALAEOZOIC COCKROACHES. 



erably less than one-fourth the width of the wing, and thereafter approaches the costal 

 margin very gradually, terminating, presumably, just before the apical sixth of the wing ;* 

 in the fragment preserved it emits three longitudinally oblique, straight branches, of which 

 the first is simple, the second simply, and the third doubly forked. The scapular vein is 

 straight, and parallel to the costal margin, lying close beside the mediastinal vein, and, first 

 dividing in the middle of the wing, probably terminates before the tip ; its branches, two 

 upon the fragment, are sublongitudinal, at least the first forked. The externomedian vein 

 is strongly arcuate, curving downward to the middle of the inner margin, and emitting 

 eight branches at a wide angle, all of them arcuate, the first nearly longitudinal, the suc- 

 ceeding ones gradually more and more oblique ; the first must originate far toward the 

 base of the wing, and does not fork unless near the tip, where it probably does ; the next four 

 branches are all forked near the middle of the wing, and probably fork again apically ; the 

 lower three are simple, so far as they can be traced, and probably remain so ; these branches 

 are more distant than those of the upper part of the wing. The internomedian vein is 

 wanting, but four of its branches (perhaps all there are) can be seen, the outermost forked, 

 the others simple, about as distant as the externomedian branches, very arcuate, and 

 obliquely transverse. 



The wing is a small one, the fragment measuring 6.25 mm. in length, and 5.7-3 mm. in 

 breadth; probably the length of the wing was 13 mm. and the breadth 6 mm., making the 

 breadth to the length as 1 : 2.2. The interspaces, particular^ in the internomedian area, are 

 filled with very frequent cross nervules. The fragment is exceedingly imperfect, not more 

 than one-third (a middle piece) of the wing being preserved ; but, excepting that it wants 

 the anal furrow, this contains the most important part of the neuration, which differs 

 widely from that of any other cockroach excepting the European species with which we have 

 generically associated it; from this it differs in its presumably greater comparative breadth, 

 the comparative sparseness of the neuration, and the downward curve of all the externo- 

 median branches ; the externomedian and scapular veins are also certainly separated much 

 further toward the base, if not altogether, and the distribution of the scapular branches is 

 different. 



In m}' former description of this insect, so different is the neuration from what appears in 

 other American species, I mistook the internomedian for an anal field, and did not attempt 

 to interpret the other parts of the neuration. I also compared it, with no show of reason, 

 to Etobl. carbonaria, with which it has no special relationship whatever. 



The single specimen known was found at Cossett's pit near Sydney, Cape Breton, by Mr. 

 A. J. Hill, C. E.. together with Libellula carbonaria Scudd., and a frond of Alethopteris. It 

 was kindly sent me for examination by Principal Dawson, who informs me that it comes 

 from a rather lower horizon than that in which the Cape Breton species of Mylacris 

 occurred, or in the lower part of the middle coal formation near the upper limit of the 

 millstone grit. Lower carboniferous. 



1 In the plate, the line which represents the mediastinal as if it were the continuation of the second forked medias- 

 vein in the middle of the fragment is unfortunately oblique, final branch; instead of parallel to the margin, as it should be. 



