Vol. 67.] EllOH THE SOUTH WALES COALFIELD. 161 



(Etoblattina) venusta, but the differences are sufficiently strong to 

 merit specific rank, where, as in this group, specific identity is 

 wholly dependent upon wing-structure. The sub-costal vein is 

 strongly curved proximally, reaching almost to the middle of the 

 base of the wing. Farther away it is parallel to the margin, and 

 then passes rapidly forward and outwards in an oblique line, 

 reaching the margin at the outer edge of the middle third of the 

 wing. The subcostal area is thus wide at the base of the wing, and 

 narrows outwards, ending in an acuminate peak against the tip of 

 the distal vein. It gives off anteriorly nine, possibly ten, branches, 

 of which the 4th, 5th, 6th, 9th, & 10th are forked, the Gth forking 

 twice. The direction of the veins becomes more oblique to the 

 margin from the base outwards, the last two being almost in a 

 straight line with the sub-costa itself. The sub-costal area forms 

 a shallow concave trough, bounded by the upturned margin an- 

 teriorly, and posteriorly by a flattened ridge which bears the bases 

 of the radius and the median vein. A. wide interval separates the 

 sub-costa from the main stem of the radius, the interval being as 

 wide at the base as at the level of the first forking of the latter. 

 The first four branches of the sub-costa are slightly elevated above 

 the general surface, the rest being flat, or, in the outer branches, 

 sunken. 



The main stem of the radius is gently arcuated, and follows 

 a course parallel to that of the sub-costa, until the first fork 

 is reached, when it begins to curve backwards, so that the two 

 anterior veins are in this region separated by an unusually wide 

 interval. The proximal third of the radius is strongly elevated, 

 as is also the first branch up to its bifurcation. The latter arises 

 at a point a little in advance of the level at which the first branch 

 of the cubitus is given off, and, curving first forward and then a 

 little backwards, passes out to the margin, giving off three forked 

 branches of considerable length in its course. The marginal veins 

 are parallel with one another, and with those of the sub-costa ; and 

 so the greater part of the anterior margin is marked out into 

 eighteen to twenty strips with parallel sides. Beyond the first 

 bifurcation the radius forks twice, once just above the middle of 

 the wing, and again at a point apparently equidistant between the 

 first fork and the apical margin of the wing. The precise position 

 cannot be determined, owing to the alar structure being torn 

 away around the critical area. All the minor veins are sunken, 

 those of the anterior branch in the concave depression which 

 passes outwards from the sub-costal area, those of the posterior 

 branches passing across a flat apical area. The whole course of the 

 radius follows a somewhat sigmoidal curve, the latter becoming 

 flattened in the hinder portion of the radial margin. 



The media arises in actual contact with the base of the radius, 

 or is united thereto. It rapidly diverges until it becomes parallel 

 with the inner branch of the radius, with which it keeps parallel 

 until the first forking is reached at the end of the first third of the 



Q. J. G. S. No. 265. m 



