40 Annals Entomological Society of America [Vol. XV, 



plate is extremely vestigial, distinctly more so than in the 

 female, though prominent enough in the nymph. The para- 

 procts are also rather small and membranous. 



The genitalia are bulky and very irregular. As in certain 

 Phasmoidea, Blattoidea and Mantoidea there are two large 

 lobes, (paramere lobes, rl, llj separated by an oblique fissure, 

 extending from about the mid- ventral line to the middle of 

 the left side at the base of the tenth tergum. Both lobes project 

 somewhat beyond the margins of the coxites, the exposed parts 

 of their ventral surfaces being somewhat chitinized. There is 

 no chitinized dorsal surface as in the Phasmids, but just below 

 the paraprocts there is a narrow transverse chitinous plate, 

 divided lengthwise into two parts, each of which is elevated at 

 the right extremity into a rounded backward projection. This 

 may represent the dorsal plate of the Phasmids, the projections 

 being perhaps homologous with the right cornu or paramere, 

 but it might not unreasonably be also compared with the 

 pseudosternite. 



The right lobe bears upon its dorso-caudal surface a heavily 

 chitinized prominence (cl), divided into two parts, which are 

 irregularly folded and bear several blunt tooth-like processes. 

 This prominence, together with the processes mentioned in the 

 preceding paragraph, and the spur of the right coxite, with 

 which they are closely associated, appear to form a clasping 

 apparatus, in which the left arm of the tenth tergum m.ay 

 perhaps be included. 



The left lobe is wholly membranous, except a small ventral 

 chitinized area, but it is produced into a long, thin-walled, 

 tubular sac, which is doubtless normally invaginated, when not 

 in use. 



The presence of the chitinous prominence on the right side, 

 but not on the left, is suggestive of the Phasmid, Diapheromera 

 (q. v.), and the eversible sac of the left lobe much resembles 

 that of many Blattids, such as Blattella and Parcohlatta, except 

 that in the latter the sac forms a sheath for a protrusible hook, 

 while in Grylloblatta no such hook is present, and it is therefore 

 difficult to conjecture as to what its function may be. 



The opening of the ejaculatory duct could not be found in 

 the single adult male of Grylloblatta available for study. It 

 will almost certainly be found in the fissure between the two 

 lobes. The mesoventral angle of the left lobe is produced into 



