122 S. H. SCITDDER ON PALAEOZOIC COCKROACHES. 



middle of the basal half of the wing, and the main stem terminates on the costal margin 

 a little beyond the middle of the apical half of the wing, keeping widely distant from 

 the mediastinal vein throughout its course ; it emits numerous parallel, straight, longitudinal 

 and forking branches, most of which, in the only species known, originate from a vein 

 parallel to the main stem, which is emitted abruptly from near the base of the second 

 branch ; the first branch terminates at the extremity of the inner margin, so that the 

 entire apex of the wing belongs to the scapular area, which is the largest in the wing. 

 The externomedian vein branches near the middle of the wing, and before that is equally 

 separated from the neighboring veins by a wide space ; it has only two or three branches 

 which are superior, and perhaps simple, and they occupy a very restricted area, only the 

 apical fourth of the inner margin being covered by their extremities. The internomedian 

 vein is again very peculiar, this being the only genus known in which a wide space 

 intervenes between the anal furrow and the branches of this vein ; it assumes to a consid- 

 erable degree the form of the externomedian vein, first branching beyond its middle, and 

 then emitting a very few simple or forking, but inferior branches. The anal furrow is 

 conspicuous, very arcuate, originating in the middle of the base of the wing, and terminat- 

 ing in the middle of the basal half of the inner margin ; it is rendered more conspicuous 

 by the fulness of the anal area, which breaks the regular continuity of the margin at the 

 extremity of the anal furrow, a peculiarity occurring in no other carboniferous cockroach ; 

 the anal veins are very few, sinuous, subparallel, simple and oblique. The wing is of the 

 average slenderness, the breadth being contained in the length about two and six- tenths 

 times. Nothing is known of other parts of the body. 



This most exquisite of the carboniferous cockroaches is very widely separated from the 

 rest. The peculiarities of nearly every part of the wing separate it at once from nearly 

 every other genus; the extreme narrowness of the mediastinal area, the wide separation of 

 the main veins from one another (accounted for perhaps by the excessive development 

 of reticulation), the independence of the internomedian vein, and the fulness of the inner 

 margin in the anal area, occur nowhere else ; the inferior origin of the branches of the 

 scapular vein are found elsewhere only in Hermatoblattina, and the wide extent of the 

 area occupied by the combined scapular and externomedian branches are reproduced only 

 in the aberrant genera among which it is placed. From Progonoblattina it is separated by 

 the small space, and that wholly on the inner margin, which is allotted to the externomedian 

 veins, besides the points first mentioned ; and from Petroblattina, its other nearest ally, it is 

 conspicuously distinct both by the nature of the externomedian vein, and by the wide 

 separation of the main veins in the basal half of the wing. 



The genus is only known from Europe, and is the only one represented by a single 

 species, which is of rather small size. More than twenty years ago Giebel suggested that 

 this species should form the type of a distinct genus. 



Oryctoblattina reticulata. PL 4, fig. 13. 



Blattina reticulata Germ., Verst. Steink. Wettin, vii, 87-88; viii, taf. 39, fig. 15% 15 b ; — 

 Gieb., Deutschl. Petref, 637; — lb., Ins. Vorw., 316 ; — Gold., Faun, saraep. foss, ii, 10. 



Fore wing. The wing is of a very graceful form, oblong obovate, the costal margin 

 tolerably convex next the base, with a very slight humeral lobe, beyond very gently and 



