796 



ARTHROPODA 



PHYLUM VII 



viTV iH'.'irly 1( 

 less irro'nilar : 



llie hypothetical type, 

 tlie anal lobe Is not 



Tlie cross-veins are numerous and more or 

 by a fold ; the anal veins are always 

 well developed, more or less branclied, 

 and curved regularly backward to tlie 

 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 

 Insects. They are restricted to the 

 Paleozoic, and occiir in various 

 European and North American 

 localities. There are about 120 

 known species, the majority of which 

 are European, and about one-fourth of this nuniber being 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 Goal Measures, 

 Many of these Insects attain considerable size. The foUowing named families liave 

 been distinguished : 



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



Fig. 1531. 

 Diagram of the neuration of a primitive insect wing, one 

 of the Palaeodictyoptera. The principal longitudinal veins 

 are connected by a network of cross - veins. c, Costa ; sc, 

 Subcosta ; r, Radius ; rs, Radial sector ; m, Media ; cu, 

 Cubitus ; a, Anal veins or nervures (after Handlirsch). 



Fig. 1532. 



rJUa^^r^" ^^f"- ßfong»- Stephanian (Upper Carboni- 

 ferous) ; Commentry, Allier, France. The antennae ocelli and 

 tarsi are reconstructed. 2/3 (after Handlirsch). ' ^ 



Fig. 1533. 

 Eublephis danielsi Handl. Goal Measures ; 

 Mazon Creek, Illinois. The antennae. ocelli 

 and tarsi are reconstructed. 2/^ ' (after 

 Handlirsch). 



L thoZ tl ' /^Wtüidae, HypermegetMdae, Mecy>opteridae, Syntonopteridae, 

 Fouaul r;..^^"T?^''^ Homoipteridae, Homothetidae, Heolidae, Broyeriidae 

 f~nted ,':Ä""'f%«P''^Pt«"dae, Lamproptüidae, Polycreagrida;, Eubleptida 



t Order 2. MIXOTERMITOIDEA Handlirsch. 



I 



