342 
Psyche 
[September-December 
Opisthocladus, new genus 
Fore wing: slender, apparently much as in Toeocladus. Costal 
area of moderate width, its basal portion thickened and heavily 
sclerotized; SC ending on R1 beyond mid-wing and giving rise to 
several strong cross veins, some of which are at least slightly sig- 
moidal or which may be looped together, forming an irregular 
submarginal vein; oblique cross veins extend from R1 to the costal 
margin beyond SC; RS arising well before the end of SC, con- 
nected to or possibly coalesced with Ml +2 for a short distance; 
M arising independently from wing base; CU forking close to wing 
base into CUA and CUP; CUA forming 3 or 4 long branches; CUP 
remote from CUA, the broad space between having several cross 
veins that form at least a few large cells; CUP rests in the anal 
fold basally, but diverges from it distally; 1A very close to CUP; 
several other well developed anal veins. Cross veins probably as 
numerous as in Toeocladus. Hind wing unknown. Body structure: 
head relatively large, with prominent eyes, dentate mandibles; 
thorax large, the segments very distinct; abdomen short, as pre- 
served, apparently compressed; cerci unknown. 
Type species: Opisthocladus arcuatus, n.sp. 
This genus differs from Toeocladus by having looped costal 
veinlets, the late origin of RS, and the longer and straighter basal 
portion of CUA. RS almost certainly has fewer branches than in 
Toeocladus, but that is not definite, since the apical part of the 
wing is not preserved. The basal portion of the costal area is 
heavily sclerotized in Opisthocladus; this may have been the case 
in Toeocladus also, since the basal part of the wing is unknown 
in that genus. 
The generic name is derived from the classical Greek words 
opistho- (hinder) and klados (branch), and is considered mascu- 
line and singular. 
Opisthocladus arcuatus, n.sp. 
Figure 4 
Fore wing: length (as preserved), 13 mm; width, 4.5 mm; esti- 
mated complete length (based on proportions of Toeocladus ral- 
lus ), 17 mm. Costal veinlets mostly oblique and sigmoidal; M 
forking just before origin of RS; CUA connected to M by a short. 
