CLASSIFICATION OF PALEOZOIC INSECTS. 345 



cult to determine whether certain veins belong to the upper or under wings, but it would 

 appear as if the mediastinal vein were shorter than usual, not reaching the middle of the 

 outer half of the wing, and that the scapular vein had four or five forking and curving 

 branches, which occupied nearly one half the area of the wing. The neuration would 

 appear to bring the species in this group, and I have accordingly placed it here, but with 

 reserve. Length of body from front of head (excl. appendages) to tip of abdomen 45 mm., 

 of head 3.5 mm., breadth of same 2 mm., apparent breadth of prothorax 6 mm., apparent 

 length of same 4.5 mm., probable length of wing 42 mm., breadth of same 12 mm., width 

 of abdomen 3.5 mm. 



Mazon Creek, 111. Found by Mr. F. T. Bliss and now in my collection. 



Perhaps in this vicinity comes another moderately slender species (pi. 32, fig. 5) which 

 is very imperfectly preserved. Very little of the wing structure can be made out, but the 

 general arrangement seems to be much as in Gerarus and to be most nearly allied to what 

 is found in the preceding species. The wings are about 20 mm. long. It comes from 

 Mazon Creek, where it was obtained by Mr. F. T. Bliss. 



G-erarus Danae. PI. 31, fig. 5. 



Miamia Danae Scudd., Geol. Surv. 111., in, 566, fig. 1. 



This species differs from the others placed here by the longitudinal disposition of the 

 veins, which have little obliquity in them. The mediastinal vein extends nearly to the tip ; 

 the apical scapular branch is compound, but the others simple ; a few cross veins may be 

 seen. It is the smallest species in this genus. The body is very vague but shows enough 

 to prove that it was much elongated. The thorax looks as if it had a median furrow. The 

 wings were apparently about 25 mm. long ; their breadth is 8 mm. 



Carboniferous deposits of Mazon Creek, Illinois. 



Adiphlebia {»■-• Sis. <j>\e'(3iov) gen. nov. 



Body rather stout, of subequal breadth throughout the thorax and basal two-thirds of the 

 abdomen, the latter tapering apically, and the obscure parts in front of the prothorax tri- 

 angular and about as long as one of the thoracic joints. Wings rather broad, well rounded, 

 with straight costa. All the nervules arising from the main stems in the basal third of the 

 wing and extending without any forking, sub-parallel, scarcely divergent, straight and lon- 

 gitudinal throughout the wing, giving it a very unusual appearance. 



Adiphlebia Lacoana. sp. nov. PI. 32, fig. 6. 



The mediastinal vein runs to the declivent portion of the costal margin, the scapular in 

 close proximity to it, throwing oft' three branches only, close together at the root of the 

 wing, which run parallel to each other unbroken to the tip, where they do not fall below 

 the middle. It is impossible to tell to which veins all the subsequent similarly simple ner- 

 vules belong, as they also part from one another and their main veins at the very root 

 of the wing. Length of body 31 mm., of abdomen 17 mm., breadth of body 5.25 mm., 

 length of wing 25 mm., its width 9 mm. 



Mazon Creek. 111. R. D. Lacoe.No. 2057. 



