3oo 
Psyche 
[December 
an attempt to uncover more of it. The results were much better than 
expected : the greater part of the head, the beak and one antenna 
were excavated. (Plate 25, figs. 2 and 3). The head is about 7 mm. 
anterior to the base of the fore wing pad and the beak extends 
obliquely into the matrix. The head across the eyes is 4.5 mm; the 
beak itself from the level of the eyes to its apparent end is 7 mm. 
long, but it may have been a little longer. On each side of the main 
part of the beak there seems to be a long segmented palpus, similar 
to that found in the Palaeodictyoptera; as in the latter, also, the 
clypeus is swollen and ridged. Although the existence of a beak in 
the Megasecoptera has been known for several years, this is the first 
specimen which has given any details of structure. So far as can 
be seen, it is formed like that of the Dictyoneuridae and other Palaeo- 
dictyoptera, though not as long as that in the Eugereonidae. One 
antenna is visible on the left side of the head of the specimen of 
Lameereites ; this can not be seen under alcohol or glycerin but 
only under oblique light. Thirteen segments can be distinguished 
(plate 25, fig. 3), the first three of which are much longer than the 
others. The antenna is at least 5.7 mm. long but since its distal 
portion is very faintly preserved, it could be somewhat longer. 
The most significant feature of Lameereites that has been re- 
vealed in the course of this study is the presence of the beak. This, 
along with the wing venation, establishes beyond doubt its relation- 
ship with the Megasecoptera, although not enough details of structure 
are known to associate it with any one family. However, the wide 
space between MA and Rs and the absence of rows of cross veins 
eliminate the Mischopteridae and related families. 
The nymph in the Douglass collection is much better preserved 
than the type of Lameereites , showing the head, beak, antennae, wing 
pads and many details of the thorax and abdomen. All of these 
structures turn out to be close to those of the adult Mischopteridae, 
which seems the most appropriate assignment for the nymph at this 
time. Of the two known genera of Mischopteridae, Mischoptera 
and Psilothorax } the former is obviously closer. Since establishment 
of a separate genus for the nymph seems inadvisable, there being no 
other nymphs for comparison, it is placed in the genus Mischoptera. 
Although the family Mischopteridae is otherwise known only from 
the Upper Carboniferous (Stephanian) of Commentry, France, its 
presence in the somewhat older Illinois nodules is not surprising; 
evidence for close relationship between the Mazon Creek and Com- 
mentry insect faunas has already been noted (Carpenter, 1967). 
