The first thing that would strike an observer, looking at the ancient Cockroaches, would be their _general_ resemblance to the living. Excepting for their usually larger size,[194] were we to have the oldest known Cockroaches in our kitchens to-day, the householder would take no special note of them--unless, indeed, the transparency of their wings (shortly to be mentioned) were to give them a somewhat peculiar aspect. There would be the same rounded pronotal shield, the same overlapping wings, coursed by branching veins, the same smooth curves and oval flattened form of the whole creature, and doubtless also the same scurrying movements. Indeed, some accurate observers--so, I suppose, we must call them--have failed to take note of some important and very general distinctions between the living and the dead. Thus Gerstaecker, in a work begun twenty years ago, and not yet finished, said, near its beginning,[195] “Not a single species of Insect has yet been found in the Carboniferous rocks which does not fall, on closer examination (_mit voller Evidenz_), not only in an existing order, but even almost completely in the same family as some living form, and only presents striking distinctions when compared with the species themselves.” He further specifies the Cockroaches described from the Coal Measures, by Germar and Goldenberg, as agreeing in every distinguishing family characteristic with those of the present day. [194] Yet none were so large as our largest living forms; their average size was very nearly that of _Periplaneta americana_. [195] Die Klassen und Ordnungen der Arthropoden. Leipzig, 8vo, p. 292.