330 SAMUEL II. SCDDDEE ON THE 



the apex of the wing, part from the under side of the (single stem. The anal area is 

 broader and the veins more numerous in the hind than in the front wings, but in both they 

 are tolerably simple and take the course of the externomedian branches ; near the base 

 they arc separated by a broad space from the internomedian branches, a space which is 

 occupied in both wings by a number of longitudinal arcuate wrinkles or independent cross 

 veins, difficult fully to understand. The front wing is -broadest about the middle; the 

 hind wing, notwithstanding its basal expansion, in the middle of the outer half. 



It may be added that on. the same stone (reversed of course on its counterpart) the 

 scapular vein of the front wing is depressed, and the externomedian and internomedian 

 veins with all their branches raised ; while in the hind' wing, the mediastinal vein, the exter- 

 nomedian vein and its branches, and the branches (only) of the internomedian -vein are 

 depressed, while the scapular, the supplementary binding vein and the main internomedian 

 are elevated ; showing that on this stone (the one drawn) we see the two wings of one 

 side, one of them upside down. Length of wings 4o mm., breadth 14 mm. 



Carboniferous deposits of Mazon Creek. From the collection of Mr. R. D. Lacoe, No. 

 2047. 



Didymophleps ( 8£S«nos, 4>M» ) gen. nov. 



This is one of the most anomalous genera of this family, all the veins and branches 

 above the internomedian being longitudinal and nearly parallel to each other and the 

 straight costal margin ; the externomedian vein is twice forked not far from the base of 

 the wing, and all the branches run in the same general direction ; so does the internome- 

 dian vein, which is exceptionally developed, and emits a considerable number of rather 

 distant, parallel, oblique, rarely forked, nearly straight brandies. 



Didyniophleps contusa. PI. 29, fig.. 6. 



Termes contusus Scudd., Proc. Bost. Soc. Nat. Hist., xix, 3(10-301. 



The body is crushed past all recognition, and fragments of legs lying between the wings 

 only show that they were slender. The wings, also, are only partially preserved, their 

 liases being destroyed with the crushing of the body and their tips by extending beyond 

 the edge of the nodule in which they are enclosed ; more than half of each wing remains, 

 however, comprising some of the more important parts. All the veins from the marginal 

 to the internomedian inclusive, as far as they are traceable on the stone, are nearly straight 

 and parallel ; the upper three are also simple, and the scapular area is considerably and 

 uniformly depressed ; the externomedian vein is forked near the base of the wing and the 

 space included between the forks, as well as the externomedian area, is traversed by feeble, 

 inequidistant, straight or oblique cross veins. The internomedian vein traverses the middle 

 of the wing, or runs scarcely above it. and emits from its lower holder a large number of 

 oblique veins, which run, often with a slightly irregular course, to the margin of the 

 wing ; in the fragment there are eight such veins on one wing and six on the other and 

 more imperfect wing, in both eases about equidistant, but more regular and straighter on 

 the left than on the right wing , in both also one of the secondary veins, and one only, 

 arising shortly before the middle of the wing, is forked — on the left side close to its origin, 

 on the right side near the middle of its course. Both borders are perfectly preserved on 



