280 
Psyche 
[June-September 
turns out to be like that which I described in one of the MCZ 
specimens (Carpenter, 1939): relatively short and consisting of only 
four segments, the middle two being much shorter than the others 
(figure 13). This is in marked contrast to the protereismatid tarsi, 
which were very long and included five segments, the first being the 
longest and the others subequal. 
In this connection it should be noted that Tschernova has de¬ 
scribed (1965) the tarsal structure of a specimen of a mayfly from 
the Permian of Chekarda. The species (sharovi) was placed in the 
genus Misthodotes and its venation, as noted above, appears to be 
typical of that of the Misthodotidae. However, the tarsal segmenta¬ 
tion is apparently different from that of M. obtusus, there being five 
segments, the fifth being the longest, according to Tschernova’s 
description. Unfortunately, it is not clear from the description 
whether that segmentation is very distinct or only vaguely pre¬ 
served. Of course, generic and family definitions are difficult to 
decide on for the few Permian species of mayflies that are known 
and it could well be that tarsal segmentation is not significant for the 
definition of these particular genera or families. However, for the 
present it seems advisable to consider the assignment of sharovi to 
Misthodotes as doubtful. 
Of the seven specimens of Misthodotes in the Midco collection 
three belong to the following new species: 
Misthodotes edmundsi, n.sp. 
Figures 14 and 15 
Hind wing: length, 10 mm; maximum width, 3.5 mm. Costal 
margin straight near mid-wing and curving towards SC well before 
the midpoint of the costal brace, the costal area gradually tapering 
towards the base; hind margin smoothly curved, the wing broadest 
at the level of mid-wing; venation essentially as in obtusus ; two 
large, irregular maculations, one at mid-wing, its center about at the 
fork of R2+3 and R4+5; the other one smaller, just beyond the fork 
of R2+3. Holotype: No. MCZ 5184ab, collected at locality 15, 
lower layer, Midco insect bed, Noble Co., Oklahoma, by F. M. 
Carpenter (1940). This is a perfectly preserved hind wing (figure 14). 
Paratypes: no. MCZ 5194, a hind wing, complete but not so well 
preserved as the holotype; length, 10 mm., width, 3.5 mm; no. MCZ 
313ab, a hind wing, complete; length 9 mm.; width, 3 mm. 
