262 
Psyche 
[June-September 
Comparative Zoology contains about 8,000 specimens from that 
deposit. Most of them were obtained on the 1940 expedition but 
others were found from 1948 to 1957. All were collected at the 
localities listed in Part 1 of this series of papers (Carpenter, 1947). 
Several years after the publication of that part, Dr. Paul Tasch of 
the Department of Geology, University of Wichita, Kansas, made 
several collections of fossils in extensions of the Midco beds or in 
associated deposits, mainly for the purpose of obtaining Conchos- 
traca, in which he was especially interested; and with an associate, 
Dr. J. R. Zimmerman, he published a brief account of some of the 
insects found there (Tasch & Zimmerman, 1962). I am indebted to 
Dr. Tasch for placing at my disposal certain of the types in his 
collection, as well as some unstudied specimens. 
The previous part of this series of papers dealt with the palaeop- 
terous orders Megasecoptera, Diaphanopterodea [included as a 
suborder of Megasecoptera], Protodonata, and Odonata. The pres¬ 
ent paper covers the remainder of the palaeopterous orders, the 
Ephemeroptera and Palaeodictyoptera. 
Order Ephemeroptera 
Three families of mayflies are known from Permian deposits: 
Protereismatidae, Misthodotidae (including Eudoteridae) and Pal- 
ingeniopsidae. 1 . 
The first two of these families are well represented in the Midco 
beds. Adult mayflies, however, are not nearly as abundant in the 
Midco deposit as at Elmo, in Kansas. Over a hundred adults have 
been found in the Elmo beds in collections including about 8,000 
specimens; only 26 adults have been found in the Midco beds in an 
approximately comparable collection. On the other hand, nymphs 
of mayflies, which are virtually absent at Elmo, are exceedingly 
abundant in the Midco beds. 
Family Protereismatidae Sellards 
Protereismephemeridae Sellards, 1907:345. 
Protereismatidae Handlirsch, 1919:63 
Protereismatidae Tillyard, 1932:237; Carpenter, 1933:489 
Kukalovidae Demoulin, 1970:6 (new synonymy) 
I consider this to be a distinct family, not synonymous with Mesephemeridae. 
