70 FOSSIL INSECTS OF THE BRITISH COAL MEASURES. 



of a stout vein which forks before the middle of the wing is reached, are dis- 

 tinguishable. The latter vein occupies the position I should assign to the radius. 

 No further traces of veins are visible. 



The two wings are separated by an interval of 3 mm. at their bases. No 

 definite details can be made out in the thoracic region. Behind the hind-wing 

 are faint impressions of a series of abdominal segments. These are about three 

 times as deep as wide, and appear to have borne lateral spiny processes. There 

 are also traces of tubercles. 



The head-region is only indicated by faint discolorations. As in the case of 

 other examples of " Pteronepionites " we have met with, the remains are so filmy 

 in character, and merge so much into the matrix, that it is impossible to define the 

 outer limits of the various segments with absolute clearness, and no attempt can be 

 made at a systematic determination of characters. 



The specimen is a larval form with wings not yet fitted for flight, but with a 

 degree of differentiation in the fore-wings which indicates that they were thicker 

 and less flexible than the hind-wings. 



The abdomen is long, wide, and well segmented, the lateral expansions being 

 not unlike those of Eupholeriaferox. So closely does the abdomen resemble the 

 segmented body of a Diplopod, that in the absence of the wings we believe it 

 would be readily classed as belonging to that group, and as possessing nothing in 

 common with insects. 



It is difficult to resist the belief that these larval insects were capable of 

 crawling about in decaying vegetation, and that their larval life was thus spent, 

 until by successive ecdysis the wings had acquired sufficient strength to lift the 

 body from the ground, and enable the insect to fly. 



Family ^ENIGMATODIDTE, Handlirsch. 



1906. Haudlirsch, Proc. U.S. National Mus., vol. xxix, p. 683. 

 1906. Handlirsch, Die Fossileu Iiisekten, p. 116. 



Wing strongly arched, and broadly rounded at the apex. Anal area small, and 

 not marked off from the rest of the wing. Subcosta reaching almost to the wing- 

 apex; radius simple, and radial sector with three divisions. Median with four 

 branches. Costa represented by an oblique vein with a terminal fork, followed by 

 three simple, strongly curved anal veins. Interstitial neuration partly of regular 

 cross-nervures, and partly of a polygonal network. 



Handlirsch founded this family on an incomplete wing in which the greater 

 part of the outer border, subcosta and radius is missing. From the upper Middle 

 Coal Measures of Mazon Creek, 111., U.S.A. 



