1978] Carpenter & Richardson — Prochoroptera calopteryx 227 
most distinctive feature of their venation is the coalescence of CUA 
and M basally, and, except in the Diaphanopteridae, the coalescence 
of CUA and M further basally with R. In all the families of the 
order, M appears to arise at the point of divergence of R and CUA. 
Although the body structure of Prochoroptera is very incom- 
pletely known, the wing venation clearly shows the diagnostic 
features of the order Diaphanopterodea, and of course, as noted 
above, in all known specimens the wings are folded along the 
abdomen. However, the position of the Prochoropteridae within the 
order is still uncertain. As far as known, the most obvious evolu- 
tionary changes within the Diaphanopterodea are the narrowing of 
the wing base and the consequent increased coalescence of M A with 
RS and ultimately with R itself (See Carpenter, 1963, plate 10, figs. 
1-6). However, it now seems probable that these changes occurred 
independently within several lines of the order (Kukalova-Peck, 
1974). As a result, diagnoses of some families are very difficult to 
make, especially of those in which the wings are not completely 
known, such as the Prochoropteridae. However, it seems advisable 
to retain the family Prochoropteridae as valid and as distinct from 
such Permian families as Elmoidae and Martynoviidae on the basis 
of its venational features as presently known. 
References 
Carpenter, F. M. 
1940. Carboniferous insects from the Stanton Formation, Kansas. AMER J 
SCI 238 : 636-642. 
1947. Lower Permian insects from Oklahoma. Part 1. Introduction and the 
orders Megasecoptera, Protodonata, and Odonata. PROC AMER 
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1954. Extinct families of insects, in Classification of Insects (C. T. Brues, A. L. 
Melander, and F. M. Carpenter). BULL MUS COMP ZOOL 108 : 
777-827. 
1963. Studies on Carboniferous insects from Commentry, France. Part V. The 
genus Diaphanoptera and the order Diaphanopterodea. PSYCHE 70 : 
240-256. 
Handlirsch, A. 
1911. New Paleozoic insects from the vicinity of Mazon Creek. AMER J SCI 
31 : 297-377. 
1919. Revision der Palaozoischen Insekten. DENKSCHR ACAD WISS 96: 
1-82. 
1920. Palaeontologie, in Handbuch der Entomologie (ed. C. Schroder) (3) 7 : 
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