CLASSIFICATION OF PALEOZOIC INSECTS. 323 



illustrating the American forms, it will not be necessary to enlarge upon them here. It 

 may be added, however, that the Devonian Gerephemera falls in this group, and that 

 Brongniart is probably correct in assigning Archaeoptilus Scudd. to the vicinity of Dic 

 tyoneura. 



Archegogryllus priscus. PI. 29, figs. •_'. :;. 



Archegogryllus priscus Scudd., Proc. Bost.jSoc. Nat. Hist, xi, 402-403. 



In now publishing figures of this fossil, I place it among orthopteroid Palaeoblattariae 

 simply in accordance with my early determination of it. not wishing to speak positively as 

 to the character of so fragmentary and uncertain a specimen. The remains consist of what 

 appears to be a broken leg, and of a fragment of a wing in close contiguity but possibly 

 not at exactly the same level. The wing, as may be seen by the figure, shows only a 

 few parallel veins of varying degrees of stoutness, with one, apparently detached, crossing 

 several at an acute angle ; no sign of any margin is seen excepting in the presence above, 

 of two or three very distant, delicate, arcuate, oblique veins, apparently of the costal area. 

 The leg is broken into fragments from which an apparent saltatorial femur and a very 

 irregular tibia can be made out, the general course of each straight, but bent at a slight 

 angle with each other. They are somewhat remarkable, for the femur is smooth, has a 

 median flat area bounded by slight ridges, while the tibia is furnished with several promi- 

 nences of large size ; in modern types the prominences when they occur are found only on 

 the femur. There is a slight rounded prominence on the upper surface near the very 

 base of the tibia and another a little beyond the middle ; opposite the latter on the upper 

 surface, is a deeply cleft elevation, its hollow corresponding to the elevation on the upper 

 surface ; the basal half of the under surface is occupied by a very broad prominence, of nearly 

 equal height throughout, but slightly depressed in the middle and terminating abruptly 

 at either end. The femur is slightly larger than the tibia and more than twice as broad. 

 Length of wing fragment 15 mm., width of same 11.5 mm., length of femur 10 mm., 

 greatest breadth of same 3.1 mm., length of tibia 8.5 mm., breadth of same at base 1.5 mm., 

 at tip 1 mm. More has been uncovered since its first description. 



The specimen was obtained by Dr. J. S. Newberry in the lowest cold beds at Talhnadge, 

 Ohio. 



[Neuropteroid Palaeodictyoptera.] 



Palephemeridae Scudder. 



This name has just been proposed by me 1 for the ancient Ephemeridae, in which the 

 lower seems to be formed on the same plan as the upper externomedian stem. The 

 ancient types are distinguishable from their fellows, as the modern are from most of theirs? 

 by the great number of cross veins breaking the interspaces into generally quadran. 

 gular cells larger then the fine irregular reticulation of other paleozoic insects. The 

 following insects may be referred here : — 



Pahphemera antiqua Scudd., Dev. Ins. N. Brunsw. 7, pi. 1, f. 5, 9, 10 ; Devonian, St. John, 

 New Brunswick. 



1 Earliest winged ins. Amer., Cambridge, 1885, p. 4. 



