84 FOSSIL INSECTS OF THE BRITISH COAL MEASURES. 



Family (EDISCHIIDJE, Handlirsch. 



1906. Handlirsch, Proc, U.S. National Museum, vol. xxix, p. 700, and Die Fussileu Insekten, p. 142. 

 1919. Haudlirsch, Revision der Palaozoischen Insekten, p. 39. 



Radial sector coalescing with the main stem of the median, and branching as if 

 a part of the latter vein. 



Handlirsch regards the family as closely related to the Sthenaropodidae. 



Genus GENENTOMUM, Scudder. 



1885. Genentomum, Scudder, Mem. Bost. Soc. Nat. Hist., vol, iii, p. 329. 

 1893. (Edischia, Brongniart, Faune Eiitom. Terr. Prim., p. 559. 



Generic Characters. Wings about three times as long as wide ; principal veins 

 and their branches well spaced, and united by a series of straight and well- 

 defined nervures. Apex of wing obtuse. 



Considerable doubt exists as to the true relationship of this genus, Scudder 

 referring it to the Homothetidse, Brauer considering it to have affinity with the 

 Sialida?, while Brongniart placed it with the (Edischiidse. 



Genentomum (?) subacutum, Bolton. Plate V, fig. 4. 



1911. Genentomum subacutum, Bolton, Quart. Jouru. Greol. Soc., vol. Ixvii, p. 334, pi. xxvii, 

 figs. 18, 19. 



Type. Two small wing-fragments, 9 mm. in length, and 6 mm. in breadth; 

 Bristol Museum (no. C. 972). 



Horizon and Locality. Lower Coal Measures (637 feet below the Bedminster 

 Great Vein, and 137 feet above the Ashton Great Vein) ; South Liberty Colliery, 

 Bristol. 



Description. One wing is partly superposed on the other, and the lower is also 

 partially concealed by shale. The upper wing is represented by a portion of the 

 distal inner portion, and by the wing-apex which is bluntly rounded. The outer 

 margin is broken away, and the original size and shape of the wings cannot be 

 determined. 



The manner in which the wing-fragments are exposed on the shale renders 

 systematic analysis of the neuration impossible. All the veins are narrow and sunk 

 in the wing-membrane, while the interstitial neuration consists of transverse 

 nervures arranged at right-angles, and dividing up the various areas into quad- 

 rangles. Where forking of the principal veins takes place, the resultant branches 

 first diverge rapidly, and then pass outwards in parallel lines and at right-angles 

 to the margin. 



