xii. palaeodictyoptera : or the affinities and classification of paleozoic 



Hexapoda. 



By Samuel H. Scudder. 



Read February 18, 1885. 



lirfXCEPTING the cockroaches, which form so large a proportion of carboniferous insects, 

 most of the known paleozoic hexapods have long been referred to Neuroptera. But the 

 opinion has been gradually gaining ground that (1) tbe wide divergence of some of them 

 from post-paleozoic as well as from existing forms, and (2) the occasional unexpected 

 proofs of the combination in single individuals of characters now only known to exist 

 separately in insects of distinct ordinal divisions, i.e., the appearance of broadly synthetic 

 or generalized types, required sonic modification of our earlier notions. The discovery of 

 Eugereon and the discussion of its structural peculiarities by Dohrn, Hagen, Gerstaecker, 

 Snellen van Vollenhoven, Packard, Brauer, Goldenberg, etc., did more than any thing 

 else to suggest and enforce this opinion. 



Dohrn himself in his very earliest paper went so far as to propose to place Eugereon in 

 an ordinal group apart under the name of Dictyoptera. and in the following year to add 

 to the same order the group of insects then known under the name of Dictyoneura. Ten 

 years later, in changing this ordinal name to Palaeodictyoptera, on account of previous 

 employment of Dohrn's term, Goldenberg also included in it the types described by Dana as 

 Miamia and Hemeristia, and Beneden's Omalia ; Brongniart has of late years employed it 

 in much the same sense, his only really distinctive addition being that of Geinitz's Ephe- 

 merites 1 . 



The recent startling discovery by Brongniart of insects plainly related in no very distant 

 way to modern Phasmida, — a highly specialized and unique group of Orthoptera, — but yet 

 hearing wings whose venation compels us to connect them directly with the synchronous type 

 of Dictyoneura, 2 and which had heretofore been supposed either neuropterous or to belong 

 to an archaic type some of whose members showed distinct heinipterous characteristics; — 



1 In his latest writings Brongniart, inlhnmed no doubt by viously accepted by Brongniart, ami whieb the recognized 



the striking combination of neuropterous and orthopterou laws at" nomenclature will not, allow US to set aside; 2, as a 



characters which he discovered in Prptqphasma and Titano- distinctive term his tails to cover the synthetic characters of 



phasma, has endeavored to supplant this term by Ndvror- the entire group (cf. Eugereon) ; -i, the accepted language 



thopteres. Three distinct objections ran lie made to this: of nomenclature is Latin and not French. 

 1. The group already has a good name which has been pre- - See Proc. Anier. Acad., xx, 167-173. 



