On a New Form of Blattoid from the Coal Measures of the Forest of Dean

Abstract

I am indebted to Dr. A. Morley Davies, F.G.S., for the opportunity of examining and describing a blattoid forewing or tegmen collected upon the spoil-heap of the Harrow Hill Mine, Drybrook (Forest of Dean), during the course of a visit to that place by a party of students from the Imperial College of Science & Technology in 1921. The wing is a right forewing or tegmen, and lies upon a block of grey shale containing plant-remains. The tegmen is somewhat large for a blattoid, having a length of 44 mm., and a greatest width (across the anal area) of 19 mm: it is thus a little over twice as long as wide. The surface is densely chitinous and lustrous, with sunken veins, while the wing presents structures not hitherto seen, so far as I know, in any other British or European blattoid. The outer (costal) margin is moderately convex along the proximal two-thirds, and then curves more abruptly inwards over the distal third, so that the wing-apex is carried backward towards the inner margin, to which it is joined by a short curve. The inner margin is convex over the anal area, concave in the middle, and a little convex over the distal cubital area, where it passes by the short curve mentioned into the blunt apex. The double curvature of the inner margin imparts to the wing a somewhat humped appearance. The costal area is very wide basally, somewhat triangular, and terminates in an acute angle beyond the middle