1 8 Lawrence B rimer 



form a horizontal squamopygidium ; pygidium simple, never with 



complex processes ; male genitalia double. 



b. Squamopygidium formed only in Gonolahina; normally all opis- 



thomeres distinct ; ninth vein of wing with a triangular area. 



(Body not strongly depressed, nor forceps sickle-shaped, except 



in Platylabiiiiac.) Protodermaptera. 



c. Metapygidium and telson not reduced, nearly as large as the 

 pygidium, which is relatively small. (Head depressed, trun- 

 cate or concave posteriorly ; femora compressed and usually 



keeled.) Pygidicranidae. 



d. Femora compressed and keeled or carinated. 



e. Antennae setaceous, with from fifteen to twenty-five seg- 

 ments, the fifth elongate. 

 /. Totally apterous, metanotum larval ; lobe of metaster- 

 num posteriorly truncate ; larvae with unsegmented 



cerci Anataelinae. 



//. Elytra always, wings usually, perfect ; metanotum with 

 combs ; lobe of metasternum posteriorly sinuate ; 



larvae with segmented cerci Diplatyinae. 



ec. Antennae with from twenty-five to thirty-five segments, 

 the fifth and sixth short. 

 /. Antennae usually heavy; fourth to sixth segments 

 transverse ; larvae with segmented cerci. 



Karschiellinae. 



//. Antennae not very heavy, fourth to sixth segments 



short, but not transverse; larvae with unsegmented 



cerci Pygidicraninae. 



dd. Femora not keeled or carinated. 



e. Prosternum convex, more or less acute anteriorly [Ameri- 

 can genera] Pyragrinae. 



cc. Prosternum not acute anteriorly [Old World genera]. 



Echinosomatinae. 

 cc. Metapygidium and telson much reduced, very much smaller than 

 the pygidium, which is relatively very large. (Sometimes the 

 pygidium is fused with the last dorsal segment, and depressed, 

 forming a squamopygidium as in Gonolahina ; head gently 

 convex posteriorly, and more or less tumid ; femora not com- 

 pressed, nor keeled.) Labiduridae. 



d. Body not very strongly flattened ; forceps not flattened nor 

 sickle-shaped. 

 e. Mesosternum strongly narrowed posteriorly. 



AUostethinae. 

 ee. Mesosternum not narrowed. 



/. Prosternum narrowed posteriorly .... Esphalmeninae. 



212 



