122 FOSSIL INSECTS OF THE BRITISH COAL MEASURES. 



Hemimylacris obtusa, Bolton. Plate VIII, fig. 7; Text-figure 38. 



1911. Hemimylacris obtusa, Bolton, Quart. Journ. G-eol. Soc, vol. lxvii, p. 154, pi. x, figs. 4, 5. 



Type. — A stout right tegmen, lying on a surface of fireclay full of Stigmarian 

 rootlets, and distorted by pressure ; Museum of Practical Geology, Jermyn Street 

 (no. 24510). 



Horizon and Locality. — Upper Coal Measures (Four-foot Seam of Swansea) ; 

 Gladys Colliery, one mile east-south-east of Penller-gaer Church, Grlam. 



Specific GJuiracters. — Costal margin convex ; subcostal vein dividing by 

 repeated forking into five twigs; costal area triangular. Radius with a radial 

 sector, the latter much divided. Median with a few forked inward branches. 

 Cubitus large, with four branches, the second twice forked. Anal area wide, and 

 crossed by numerous veins, the first giving off a simple branch, and then dividing 

 twice by equal forking. Inner margin almost straight. 



II 



1 



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Fig. 38. — Hemimylacris obtusa, Bolton ; diagram of right fore-wing with apex restored, three times 

 natural size. — Upper Coal Measures (four-foot Seam of Swansea) ; Gladys Colliery, near Penller- 

 gaer Church, Glamorganshire. Mus. Praet. Geol. (no 24510). Numbering of veins as in Text- 

 figure 33, p. 104. 



Descrijrtiort. — A short rounded right tegmen, 23 mm. long and 14 mm. wide, 

 broken across the basal third along the anal furrow, and the apex missing. 



The subcostal area is broadly triangular, the subcostal vein sunken, and 

 passing out obliquely, giving off a basal branch which forks into two equal twigs, 

 the most distal twig forking again. A single undivided branch is given off near 

 the end of the subcosta. 



The radius gives off a strong radial sector, and afterwards sends outwardly 

 three simple branches. The radial sector sends four branches to the margin, the 

 first forking twice, and the fourth once, the second and third being simple. 



The median vein appears to give off the stem of the cubitus near its base, but 

 this appearance is probably due to the crumpling of the tegmen. The first of the 

 three inward branches of the median arises further out than any of the divisions 

 of the radius or cubitus. The first branch divides into three twigs, and the second 

 forks on the broken edge of the wing. All the branches pass straight out towards 

 the wing-apex. 



