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Carpenter — Permian Insects from Oklahoma 
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the wing base does not gradually narrow but ends abruptly. The best 
specimen of the hind wing is YPM 5470 (figure 11), a drawing of 
which was given by Tillyard (1934). However, in his figure the costal 
area is shown as gradually tapering in the region of the costal brace. 
Although Tillyard stated in his description that the costal vein was 
obsolescent near the base, on examining the specimen I found that 
the base of the costa was only covered by a small piece of the rock 
matrix. On removing that I found that the costal area at the base 
was in fact like that of the fore wing, not gradually but abruptly 
narrowed. This is significant because one of the Midco species does 
have the costal margin gradually narrowed. In the same figure Till¬ 
yard included the veins of the cubital-anal area, although I find that 
there are only vague suggestions of them in the specimen. This area 
is not clear in any of the Elmo specimens of obtusus, either, but it is 
well preserved in one of the Midco specimens of Misthodotes ovalis, 
mentioned below. 
The body structure is not so well known for Misthodotes as it is 
for Protereisma. One of the Elmo specimens of obtusus in the Pea¬ 
body Museum (YPM 1100) does show some details. In his descrip¬ 
tion of this specimen Tillyard stated that the tarsi were entirely 
missing. However, one hind tarsus has now been completely 
exposed by removal of some of the rock matrix, and its structure 
Figure 13. Photographs of tarsi of Protereismatidae and Misthodotidae: A, 
Protereisma permianum, MCZ 3402, Permian of Kansas. Length of tarsus, 8mm. B, 
Misthodotes obtusus, MCZ 3402, Permian of Kansas. Length of tarsus, 1.5 mm. 
TIB, tibia; TAR, tarsus. 
