320 
Psyche 
[December 
segments (total length unknown). The prothorax was about as broad 
as the metathorax but usually only about half the length of the meso- 
thorax, with a nearly straight, or slightly concave anterior margin and 
rounded posterior-lateral margins. The meso- and metathoracic seg- 
ments were subequal, the tibia shorter than the femur; the tarsi 
were 5-segmented and there were two nearly straight claws. The 
wing pads were divergent, independent from each other and not fused 
medially in young as well as older nymphs ; they were attached to 
the thorax only along that part of the wing which becomes the 
articular region in the adult; the fore and hind wings were nearly 
equal, though the hind wing was slightly shorter; venation very 
similar to that of adult Protereisma but with MA clearly independent 
from Rs, and Rs distinctly arising from R 1 ; the costal brace was very 
strongly developed, more so than in the adults; the cross venation 
was much more reticulate than in the adults. The abdomen was 
slightly tapering, with the segmentation homonomous except that the 
first segment was somewhat shorter than the others; the cerci were 
only slightly longer than the median caudal filament; the latter had 
a dense row of hairs on each side and the cerci had similar hairs on 
the inner sides only. 
In addition to the previous nymphs, which appear to belong to 
the family Protereismatidae, there is in the collection from Obora 
at Charles University one specimen of a nymph (nymph no. 6) which 
is very distinctive. It is almost certainly not a protereismatid but its 
family position cannot be determined ; it probably represents a distinct 
family. Prothorax is formed much as in the previous nymphs, the 
anterior margin being straight but the meso- and metathoracic seg- 
ments are relatively broader and shorter. The markings on the meso- 
and metanota are distinctly different from those of the previous 
nymphs, as shown in figure 7. Legs subequal, tibia much shorter 
than femur. Wing pads relatively short only about as long as the 
mesothorax is wide; these are widely separated on the thorax but 
not so divergent as in the preceding nymphs and they are distinctly 
widened towards the attachment at the thorax; the hind wings ap- 
pear to be slightly shorter than the fore wings; the costal brace is 
not preserved and the venation is very indistinct but the costal and 
subcostal areas seem much narrower than in the Protereismatidae. 
The abdomen is relatively slender; segment 1 seems to be very short 
but it may be partially concealed under the metanotum. Gills are 
present on the first 7 segments and probably occurred on the 8th and 
9th but these segments are not preserved in the fossil; the gills are 
very long, fully twice as long as any segment. The cerci and caudal 
