... origin to the rest of the Hexapoda (see Box 7. 1). IfCollembola do belong to the Hexapoda, then they formeither the sister group to Protura comprising the cladeEllipura or alone form the sister ... aswings held roof-like over the abdomen, fore wingseither membranous or in the form of tegmina of uni-form texture, and with the rostrum arising ventrallyclose to the anterior of the thorax, ... their possession of a particular kind of gut filter chamber, a rostrum thatappears to arise between the bases of their front legsand, if winged, by absence of the vannus and vannalfold in the...