being of insects, is still merely artificial, that it is not sufficiently strict, for the order of the Suctoria is an apterous group, not in its right place among the Insecta Pterodicera. And also the groups which are here considered as equivalent to the Tetracera, Myriapoda, Apterodicera, and Pterodicera, are by no means of equal value, but the two first and two last are most closely allied; the former are the subordinate members of a higher group, and the latter also could at most be placed as equivalent to the orders of the Insecta pterodicera."
Before leaving this subject, it may be desirable to show briefly, in juxta-position with the above, some of the various changes our author afterwards made in his arrangement, for in every successive work important alterations were effected. In his "Considérations générales sur l'Ordre Naturel des Animaux composant les Classes des Crustacếs, des Arachnides, et des Insectes,"[1] the Linnean Insecta was divided into three equivalent groups, Crustacea, Arachnides (including the Insecta aptera of the former system), and Insecta. Such was likewise the arrangement which appeared in Cuvier's Règne Animal[2], but the groups were differently defined, and some of the contents of each transferred to another. There was likewise the necessary addition of the order Strepsiptera, recently discovered by Kirby. After several other changes, of more or less importance, in different works, we come to that embodying his latest views, published in his "Cours d'Entomologie,"[3] which was completed only a short time before
