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Carpenter — Permian Insects from Oklahoma 
277 
thodotes (zalesskyi and sharovi ) from the Permian of Chekarda in 
the Soviet Union.® These adults appear to be typical of the family 
except for the tarsal structure, as noted below. Kinzebach (1970) has 
published an account of a supposed mayfly from the Permian of 
Germany and has placed it with some question in the family Mistho- 
dotidae. Since the wing venation is not preserved, there is no evi¬ 
dence that the specimen belongs to the Ephemeropters. If it does, 
the long, slender legs would be more suggestive of the Protereismati- 
dae than the Misthodotidae. 
The nymphs of the Misthodotidae are not definitely known. 
Tschernova (1965) has described a fragment of a nymph from the 
Chekarda beds and identified it as belonging to Misthodotes sha¬ 
rovi. The nymph has nine pairs of gill plates, as in the protereis- 
matid nymphs, but since the entire thoracic region, including the 
wing pads, is not preserved, there is really no evidence for associat¬ 
ing the specimen with Misthodotes or even with its family. 
There are several adult specimens of Misthodotidae in the MCZ 
collection from the Midco beds, all belonging to the genus Mistho¬ 
dotes. Study of this material and reexamination of the Elmo species 
have indicated that some revision of the diagnosis of the genus is 
necessary. 
Genus Misthodotes Sellards 
Dromeus Sellards, 1907: 351 (nec Dromeus Reiche) Type species, by monotypy, D. 
obtusus Sellards. 
Misthodotes Sellards, 1909: 151. Tillyard, 1932: 261; Carpenter, 1939: 63. 
Eudoter Tillyard, 1936: 443. New synonymy. 
4 In one Elmo specimen of M. obtusus (MCZ 4388ab) the cerci and the caudal 
filament, apparently complete, are 20 mm long, or about two and one-half times the 
length of the abdomen. The full length of the cerci or the caudal filament is unknown 
in Protereisma. 
“However, Tschernova’s account of these fossils is very confusing: the labeling of the 
veins in the drawings of the wings is different from the terminology used in the 
descriptions. In her discussion of the venation she states that CUA is either 
unbranched (i.e., simple) or possesses only a short terminal fork, as is characteristic 
of the genus Misthodotes and its family. But in the figures of both species she has 
shown CUA as consisting of two long branches, labeled CUA1 and CUA2. The 
convexities and concavities of the veins are not indicated in her figures, but in the 
Oklahoma and Elmo specimens of Misthodotes the long branch that she has labeled 
CUA2 is concave and is obviously CUP. The two veins that she has labeled CUP1 
and CUP2 are of course anal veins. 
