Xn LIST OF ILLUSTRATIONS. 



Page. 



Right half of mesopectus of Sponqiphora apicidentata (earwig); Cx, coxa; CxP, 

 pleural coxal process; Epm, epimerum; Eps, episternum; Peps, preepister- 

 num; PS, pleural suture; 3, sternum; Tn, trochantin; x, plate between the 

 sternum and preepisternum 47 



Theoretical diagram of a wing-bearing tergum and base of wing: lA, first anal 

 vein; ANP, anterior notal wing process; anr, line of anterior ventral notal ridge ; 

 lAx, 2 Ax, 3 Ax, 4 Ax, first, second, third, and fourth axillaries of wing base; AxC, 

 axillary cord; C, costa; Cu, cubitus; M, media; m, median plates of wing base; 

 N, notum; PN, postnotum, PNP, posterior notal wing process; pnr, line of 

 posterior ventral notal ridge; Pph, postphragma; R, radius; 8c, subcosta; Tg, 

 tegula; vnr, line of median ventral V-shaped notal ridge 49 



Base of front wing of Asynarchus punctitissimus (caddice fly) : lA, first anal vein; 

 lAx, 2Ax, SAx, first, second, and third axillaries; AxC, axillary cord; C, costa; 

 Cu, cubitus; M, media; R, radius; Sc, subcosta; Tg, tegula 50 



Ventral surface of base of front wing of Txniopteryxjrigida: 2 Ax, ventral element 

 of second axillary; AxC, axillary cord; AxD, axillary disk; C, costa; R-\-M, 

 basal trunk of radius and media; Tg, tegula 51 



Nymph of a stonefly, dorsal view, showing wide postnotal membranous areas, 

 which, in the mesothorax and metathorax of the adult, are occupied by the 

 postnotal plates 54 



Longitudinal section through back of mesothorax, metathorax, and base of 

 abdomen of a locust (Trinierotropiis maritima): Au, "auditory organ"; CxP, 

 coxal process of metapleurum; DMcl, dorsal longitudinal muscles; Epm^, 

 epimerum of metathorax; Eps^^, episternum of metathorax; IT, first abdominal 

 tergum; J/ftg) postnotal membrane of mesothorax; iVj, mesonotum; iVg, meta- 

 notum PA, pleural arm; PN^, plate fused with first abdominal tergum {IT), 

 which is probably the postnotum of metathorax; iPh, 2Ph, SPh, anterior 

 middle and posterior phragmas; 2Sp, second thoracic spiracle 66 



Metathorax and abdomen of a long-horned grasshopper {Scudderia furcata), 

 showing the apparent postnotum of the metathorax {PN^) intimately fused 

 with the first abdominal tergum {IT): Cx^ metacoxa; Eps.^, Epm^, episternum 

 and epimerum of metathorax; IT, first abdominal tergum; N^ metanotum; 

 IP, 2P, episternal paraptera; PiVg, the apparent postnotum of metathorax; 

 S3, metasternum; Tn, trochantin; TFP3, pleural wing process 56 



Longitudinal section through back of thorax and base of abdomen of a stonefly 

 nymph {Isogenus), showing each back plate of the thorax separated from the 

 one behind it by a wide postnotal membrane: DMcl, dorsal longitudinal 

 muscles; IT, first abdominal tergum; Mb^, Mbo, Mb^, postnotal membranes; 

 iVi, pronotum; iVj, mesonotum; iVg, metanotum; TFj, front wing; PFg, hind 

 wing 58 



Longitudinal section through back of mesothorax, metathorax and base of 

 abdomen of an adult stonefly {AUoperla) showing postnotal plates {PN2 PiVj) 

 occupying position of postnotal membranes (If^a ^h) in %• 14; 2Ph, SPh, 

 second and third phragmas 58 



Corresponding section through another adult stonefly {Txniopteryx frigida), 

 showing same thing as fig. 15 



Propectus of Scolia dubia; A, lateral view; B, ventral view: Cxi, procoxa; Epnij, 

 Epimerum; Epm A, epimeral arm; Eps^, episternum; j, ridge on side of epi- 

 sternum where edge of pronotum overlaps it; I, ventral cervical sclerite; n, 

 ventral subdivision of episternum; PS, pleural suture; S^, presternum 70 



Lateral view of ant thorax {Leptogonys elongata): Cx^, CX2, Cx^, Coxae; Epm2, 

 mesepimerum; EpSi, proepisternum ; Epso, eps.,, upper and lower subdivi- 

 sions of mesepisternum; h, scuto-prescutal (parajDsidal) suture; II, second 



