1983] 
Burnham — Geraridae 
1 
of R near midpoint of wing; M either anastomosing with RS for a 
short distance or connecting to it by a cross-vein; CUA strongly 
developed, arising from base of M; CUP forked, arising independ- 
ently from wing base. 
Hind wing; length 30-48 mm; costal area not as broad as in fore 
wing; SC simple, terminating in C; R parallel to SC, terminating at 
wing apex; RS pectinate, arising from R near wing base; M forked, 
arising near base of RS; CUA and CUP simple and parallel to one 
another; CUA arising from base of RS near M, CUP arising inde- 
pendently from wing base; anal area unusually reduced; cross veins 
abundant in both fore and hind wings. 
Body; prothorax elongate, flask-shaped, and distinctively spi- 
nose; abdomen cylindrical; antennae filamentous; head small and 
probably mobile; legs cursorial, tarsi five-segmented. 
Diagnosis 
In many ways the Geraridae are typical Orthopteroidea, having 
mandibulate mouthparts, hypognathous heads, and filamentous 
antennae. But they differ from other orthopteroids in two important 
characters: their well-developed prothorax which is armed with 
spines (the latter reach a length of 10 mm in G. danielsi), and their 
distinctive fore and hind wing venation. While gerarids can be read- 
ily recognized on the basis of the prothorax alone, wing venation is 
generally a better diagnostic character. Particularly distinctive are 
the RS-M veins in the fore wing, and the R-RS veins in the hind 
wing. In the fore wing RS is reduced and M is expanded with 5 to 6 
branches. The apical branch of M either anastomoses with RS for a 
short distance or is connected to it by a short cross vein. In the hind 
wing, the opposite is true: M is greatly reduced and RS expanded 
into 5 to 6 branches. 
It is worth noting that the anal fan in the hind wing, if present, 
was very small (see fig. 17). This suggests that in gerarids the fore 
and hind wings may have functioned equally well in flight, unlike in 
extant Orthoptera, which rely primarily on expanded hind wings for 
flight propulsion. The abdomen is essentially unknown for the fam- 
ily, but was probably shorter than the wings, a claim based on the 
comparison of wing length to legs, thorax, and head. No cerci are 
preserved, but because the Geraridae are orthopteroid, it may be 
assumed that they were present. 
