18 



S. H. SCUDDER ON THE EARLY TYPES OF INSECTS. 



Goldenberg, proposes to group them under a new subordinal division, to which Goldenberg 

 has applied the name Palaeodictyoptera. 1 



This view I am inclined to think a correct one, but no definition of the group has yet 

 been attempted ; and while, on the one hand, Goldenberg appears to have gone too far in 

 referring to it the Carboniferous insects from Illinois described by Dana, and the Devonian 

 insects of New Brunswick, it would seem probable that Woodward's Archimantis 2 should 

 be classed therein, as well as the genera Eugereon, Dictyoneura, Paolia and Haplophlebium ; 

 and it is by no means improbable that they all possessed mouth parts structurally com- 

 parable to the remarkable Eugereon of Dohrn, which certainly can be referred to no exist- 

 ing group of insects. When more of their structure is known, they will probably be found 

 to agree in the possession of a remarkably depressed, cockroach-like body, with ample 

 thoracic segments, the prothorax well separated from the other joints, broadly expanded or 

 extended, reticulated wings, lancet-shaped mandibles and maxillae, long labial palpi which 

 have no direct part in the haustellate structure of the mouth, and multiarticulate antennae. 

 This is a combination quite at variance with that of any group of recent or of newer geo- 

 logical times, and indeed is known to us only in the palaeozoic rocks. It forms a synthetic 

 type in the largest sense, and may be said to combine features of all the Heterometabola. 



But it was not the only such type then existing; for, as has already been noted, there are 

 many other palaeozoic insects which combine in their structure features now characteristic 

 of diverse groups. Such are nearly all the Devonian insects. It is also not a little re- 

 markable to find that recent types existed in the earliest periods side by side with these- 

 Some of the Devonian insects, for example, are to be referred with very little question, not 

 only to the Neuroptera, but even to a particular family of Neuroptera now existing, the 

 May flies. Indeed, the presence, at the apparition of a given group, of modern types, side 

 by side with those which elude our classification of existing forms, is one of the peculiar 

 problems of palaeontology. 



Perhaps no more striking instance of this can be found than the recent discovery by 

 M. Charles Brongniart, in the upper Carboniferous rocks of Commentry, of one of the most 

 specialized forms of insects which exist ; of a type indeed so modern, that, so far as I may 

 judge from a rough sketch sent me by Brongniart, one would not have been surprised to 

 meet with its exact counterpart in every detail, living in the tropics of the old world. It 

 is a species of large, spinous, thick-bodied Phasma or walking-stick, with abbreviated teg- 

 mina, long wings and body, rather long and slender legs and antennae, and in all its parts 



1 Cf. Dohrn, Palaeontogr.,xm: 338-39; xiv: 134. Gold- 

 enberg, Faun. Sar. foss., II : 8. Dohrn first proposed the 

 term Dictyoptera, but afterwards withdrew it, as preoc- 

 cupied. 



2 Woodward. On a remarkable orthopterous insect from 

 the coal-measures of Scotland. < Quart. Journ. Geol. Soc. 

 Lond., 1876 : 60-64, pi. 9. Woodward, it seems to me, has 

 in all probability, mistaken the affinities of this insect. If 

 his figure is placed beside Dohrn 's first illustration of 

 Eugereon, the similarity of the two will be apparent. The 

 form and relations of the head, prothorax and broadly 

 expanded wings (nearly all that is preserved in Archi- 

 mantis) are the same in each, as well as, in a general sense, 



the neuration of the wings. The projection in front of the 

 head, therefore, would seem to be, not a prolongation of the 

 head itself, comparable, as supposed by Woodward, to that 

 of the head of some living Mantida? ; but a rostrum, like that 

 of Eugereon, though much shorter than it, and by its state of 

 preservation apparently amalgamated with it into a single 

 mass ; or, it may be the labrum alone with the other parts 

 removed, for it would then probably appear as an integral 

 part of the head. The close relationship of the wing- 

 structure in Archimantis, Eugereon and the other genera 

 specified above render it not improbable that they were all 

 sucking insects. Protophasma however, similarly related, 

 certainly was not. 



