82 



FOSSIL INSECTS OF THE BRITISH COAL MEASURES. 



The r;i<li;il sector avisos near the middle of the wing, and at a distance of 

 :'.S mm. from the wing-base. The angle which il makes with the radius is 

 t'aivlv la rye, and the enclosed urea must have been very wide in the outer halt 

 of the wing. 



The median arises close to the radius, and then bends inwards as it passes 

 to the inner half of the winy-apex. Its divergence from the radius is more than 

 double that of the radius from the subcosta. Povtions of two outwardly directed 

 branches are shown, the first joining the radial sector; only the base of the 

 second is preserved : it follows a course parallel with the first branch. About 

 21 mm. from the base the median gives off a strong inward branch passing 

 obliquely to the cubitns and fusing with it. The cubitus is S-shaped. being 

 convex outwardly to the junction with the commissural vein from the median, 

 and concave iuwardlv afterwards. Owing to this inward inflexion, that part 



Fin. !'.">. l.'usi'lin juilnii/in-iiii!.. <_;rii ot sp. imv . ; din i;Tain of 1>asal portion of left win ;;. showing- tin- 

 general i-liavaetfr of tin- venation, three-lialvos natural size. MieMle Coal Measures: Coseley. 

 Stall'or.lslmv. Johnson ( 'olleetion, Hrit. Mus. (no 1. l.'.MCt). 



of the cubital area Iving bevond the junction with the median is extremely wide. 

 The cubitus gives off four inwardly directed branches at wide intervals, the first 

 branch having a wide forking in the first third of its length. The branches 

 of the median must have occupied the greater part of the inner margin of 

 the wing. 



The cubitus gives off six inward branches, the first arising very low down, 

 and the remaining five at regular intervals, the first being given off a little way 

 bevond the junction with the commissural vein. The first and fourth of these 

 branches fork into two widely separated twigs. 



The first anal vein is simple, and has a broad convex outward sweep down to 

 the inner margin; the second anal vein gives off three branches on its inner side. 

 Other anal veins mav have been present, but the wing-st met lire is missing at 

 this point . 



\\ ith the except ion of the subcosta and radius, all the main veins are widely 

 spaced, and no branches arc given off, except the tirst median, m the basal third 

 of I he w ing. 



The interstitial neural ion is well marked, and of unusual character. That 



