796 



ARTHROPODA 



PHYLUM VII 



very nearly to tlie liypothetical type. The cross-veins are numerous and more or 

 less irregular ; tlie anal lobe is not separated by a fold ; the anal veins are always 



well developed, more or less branched, 

 C and curved regularly backward to the 



SC posterior margin ; and there is no 

 anal fold nor fan - like plaitings. 

 Larvae are similar to the imago. 



The Palaeodictyoptera are best 

 regarded as a generalised group of 

 very primitive organisation, and as 

 the probable progenitors of all winged 

 Pjq_ 1531 Ijisects. They are restricted to the 



Diagram of the neuration of a primitive insect wing, one Paleozoic, and OCCUr in various 

 of the Palaeodictyoptera. The principal longitudinal veins "PupniiPaTi ond ISTnT-th ATnericnn 

 are connected by a network of cross -veins, c, Costa ; sc, -CiUropean anci l^Ortn Ameiican 



Subcosta; r, Radius; rs, liadial sector; m, Media; ru, localities. There are al>OUt 120 



Cubitus; a, Anal veins or nervures (after Handlirscli)- i ■ l^ ■ ■. c t ■ ^ 



known species, the majority ot which 



are European, and about one-fourth of this number l)eing found in the Carboniferous 



of the United States and Canada. Six species are known from the Pottsville, ten 



from the Kanawha and Little River groups, eleven from the Allegheny, one from the 



Conemaugh, and the remainder of American forms from the Productive Coal Measures. 



Many of these Insects attain considerable size. The following named families have 



been distinguished : 



Dictyoneuridae, of which the genus Stenodictya Brongn. (Fig. 1532) is an example. 



'^^^^;^^m£^^^^^'''^'^' /is^^ 



f^j^A^Sdiif^ 



Fig. 1533. 



EkiblepPns da7ilelsi 'H.a\ii.\l. Coal Measures ; 

 Stenodictya lohatn Brongn. Stephanian (Upper Carboni- Mazon Creek, Illinois. The antennae, ocelli 

 ferous) ; Commcntry, Allier, France^ Tlie antennae, ocelli and and tarsi are reconstructed. -/x ' (after 



tarsi are reconstructed, "/s (after Ilandlirsch). 



Handlirsch). 



Peromapteridae, Megaptilidae, Hypermegethidae, Mecynopteridae, Syntonopteridae, 

 Lithomantidae, Lycocercidae, Homoijiteridae, Homothetidae, Heolidae, Breyeriidae, 

 Fouqueidae, Grapliiptilidae, Sjiilapteridae, Lampioptilidae, Polycreagridae, Eublejitidae 

 (represented by Euhlejptus) (Fig. 1533), Metropatoridae, Paoliidae, Stygnidae, Aenigma- 

 todidae, and Synarmogidae. 



t Order 2. MIXOTERMITOIDEA Handlirsch. 



Wings with broadly rounded apical border, their venation resembling that of the 

 Palaeodictyoptera, hid more highly specialised. 



