26 S. IT. SCTJDDER ON PALAEOZOIC COCKROACHES. 



and unequal rays spreading from a common base, much like the rods of a fan; while in 

 the other, found on both continents, the shorter and equal rays originate at regular inter- 

 vals, as branches from the side of a main vein. No such important distinction exists in the 

 cockroaches of the old world coal-measures, even in the most aberrant types; but within 

 each of these two tribes, other distinctions appear, in the relative extent or position of the 

 different areas, in the mode of branching of the main veins, or in the point of origin of 

 the branches, affording valuable data for generic distinctions, and a tolerably safe clue, it 

 is believed, to the true relationship of the species. 



The classification proposed in this paper, based upon the structure of the framework of 

 the wing, and generally neglecting its mere form or surface sculpture, may be expressed 

 briefly by the scheme on the opposite page, which will be more fully developed in the 

 body of the memoir. 



A word may be said concerning the nomenclature employed in this scheme. It will be 

 noticed that the generic term Blattina, first employed for palaeozoic cockroaches by Germar 

 and since universally adopted in the same sense, has been dropped. It is not a little 

 curious that the first four species described by Germar (and, I may add, the first American 

 palaeozoic cockroach, described by Lesquereux) all belong to a single genus as here 

 defined, namely Etoblattina, a genus at the same time the richest in species ; so that there 

 can be no doubt whatever as to which of these genera should bear the old name, if any of 

 them can do so. It were indeed to be wished that it might be retained by Etoblattina, and 

 to preserve the old name as far as possible I have retained it as a part of all the compound 

 terms I have employed to designate the genera represented in the European carboniferous 

 fauna, as well as in the tribal name which embraces them. But before Germar made this 

 use of the term Blattina, earlier indeed by about thirty years, 1 he applied it to a cockroach 

 from amber, which must be employed as the typical species, and which is utterly distinct 

 from any of the palaeozoic forms. We are therefore unwillingly compelled to reject the 

 name for palaeozoic cockroaches, and, unless indeed it be a synonym of some earlier name, 

 to employ it for the tertiary Blattarian only. 2 



The use of the term Palaeoblattariae for all the palaeozoic cockroaches to distinguish them 

 from more modern types requires also an explanation. In commencing this investigation 

 it was anticipated that the mode of distribution of the principal veins of the wing and the 

 relative area occupied by each would furnish some ground for discussing the affinities and 

 natural classification of these animals and of separating them into genera and species. 

 But the degree of divergence from living types which the palaeozoic forms exhibit, and 

 their own division into two large groups was entirely unexpected. To appreciate the 

 former distinctions, it will be best first to examine the wings of living Blattariae. 



The structure of the organs of flight in cockroaches has received an unusual share of 

 attention, principally from Messrs. Brunner and de Saussure, who have devoted a great 



'Germar. Mag. d. Entom. Jahrg. i, 16 (1813). it he placed Elohl. primaeva, Hermalobl. labacliensis and 



a In his first use of the term Blattina, Germar employed it Petrahl. gracilis. Goldenberg (In,-. ,//.) further credits 



without any explanation whatever. In Ids work on Wcltin Berendt with the first use of the term, but I cannot discover 



fossils (p. si), he says: " Blattinae nomine utimur, quo that Berendt used it either in 1 s.io or in 1836, the two oc- 



omnes species complectimur, quae antehae ad Blattae genus casions when he referred specially to fossil cockroaches; 



sunt relatae." Goldenberg (Palai togr. iv, 5) was the first while Germar certainly employed it in 1813. Nor did Rer- 



to define the, genus, as follows: " Venis omnibus areae endt use it in 1845 in the essay prefixed to Ms Organische 



analis hemelytri in marginem internum excurrentibus." In Reste im Bernstein. 



