146 FOSSIL INSECTS OF THE BRITISH COAL MEASURES. 



reaching the wing-apex, curving inwards as it does so. The junctions of the 

 branches of the radial sector are destroyed. It would seem to have begun between 

 the radius and the median as an accessory vein, rather than as an offshoot of the 

 radius. Its branches occupy the outer half of the wing-apex. The median is a 

 large and important vein, dividing near the base into two branches. The outer 

 branch is undivided until close to the distal end of the outer margin, where it gives 

 off an outer and two inner twigs. The inner branch of the median gives off five 

 simple inner twigs, and an outer one which forks close to the margin. The cubitus 

 is represented by two veins, an outer vein which remains undivided and an inner 

 which gives off at least five twigs. It is possible that the vein which I thus describe 

 as the cubitus is really part of a cubito-anal, but as the basal part is missing the 

 exact conditions cannot be determined. The inner margin of the wing is nearly 

 straight. 



Affinities. The wing-structure, so far as it can be made out, is much like that 

 of Paralogus aeschnoides, Scd., and Protagrion audouini, Brong., and of these it 

 more nearly accords with the latter in its great length as contrasted with the 

 breadth. The plication of the wing is unusually well developed, and is a feature 

 best seen in P. a&schnoides. The presence of accessory sectors is again a feature 

 seen in Protagrion. The general wing-structure, therefore, has certain characters 

 of both genera, and where it departs from the one it approaches the other. 



ADDENDUM. 

 Archimylacris pringlei, Bolton. Plate X, fig. 3. 



1921. Archimylacris pringlei, Bolton, Quart. Journ. G-eol. Soc., vol. Ixxvii, pp. 23 29, pi. i, figs. 1 2, 



text-fig. 1. 



Type. The basal two-thirds of a fore- wing, and counterpart impression, partly 

 obscured by plant remains ; Museum of Practical Geology, Jermyn Street (nos. 

 30725, 30726). 



Horizon and Locality. Keele Group, Upper Division of the Coal Measures; 

 from rocks between the surface level and 97 feet in borehole at Slang Lane, 

 Wellington, Shropshire. 



Specific Characters. Wing twice to two-and-a-half times as long as wide, 

 costal margin flattened ; subcostal area strap-shaped and very wide, crossed by 

 numerous parallel branches of the subcosta. Radius dividing beyond middle of 

 wing. Median parallel with radius. Cubitus curving to inner margin, with 

 widely separated inward branches. Anal area long. 



Description. The wing-fragment has a length of 18 mm. The costal margin 



