1971] Carpenter Richardson — Pennsylvanian Insects 
273 
cercus, although the lobes are prominent, they are membranous or 
nearly so with a radiating series of vein-like structures, as in most 
other Palaeodictyoptera ; paranotal spines are unknown in Lycocercus. 
Type species: Notorachis wolff drum, n.sp. 
Notorachis wo Iff orum, n.sp. 
Figures 4-6 
Length of wings, as preserved, 22 mm.; maximuum width of fore 
wing, 10 mm.; width across pronotal lobes, including spines, 20 
mm. 
The fossil consists of the dorsal aspect of the head, pronotum, 
and meso- and metathorax; a few segments of the abdomen are in- 
dicated and the wings are outstretched in the palaeopterous position. 
The fore and hind wings on each side overlap but the basal part of 
the venation of one wing is discernible for the most part. The 
costal space seems to be of uniform width ; the precise origin of the 
radial sector is not preserved ; MA obviously arises before the ori- 
gin of the radial sector and is probably unbranched, although its distal 
part is not preserved; MP has at least five terminal branches and 
CuP is even more extensively branched. The hind wing is almost 
completely covered by the fore wing and only a few veins can be 
distinguished. 
The most conspicuous of the body structures are the pronotal lobes 
(figures 5 and 6), which are not sharply set off from the rest of the 
prothorax. The margins of the lobes are heavily sclerotized and 
bear seven prominent spines on each side, the first and last of these 
being somewhat shorter than the others. The two posterior spines 
of each side are directed somewhat dorsally as well as laterally. 
Extending along the median axis of each lobe is a double row of 
setae (preserved in the reverse of the fossil as fine pits). The sur- 
face of the slightly elevated margin of the pronotal lobe is smooth 
along the posterior edge of the lobe; on the anterior edge it is occu- 
pied by scattered setae or fine tubercles. Similar setae are present on 
the proximal third of all the spines. Somewhat before mid-length of 
each spine the setae are smaller and directed posteriorly; in the distal 
potion of each spine, the setae are succeeded by strong, longitudinal 
ridges. 
The head is visible just anterior to the lobes but there is no sharp 
separation in the fossil between the head and thorax; two relatively 
large, circular structures are visible on the sides of the head, pre- 
sumably the compound eyes. A four-millimeter portion of one an- 
tenna is preserved; it appears to arise from above the center of the 
