In this physiologico-psychological base for a classification he unwisely departed from his usual more solid foundation of anatomical structure, and the results were worthless.

He, however, repeats it in his great work, _Histoire naturelle des Animaux sans Vertebres_ (1815-1822).
The sponges were by Cuvier, and also by Lamarck, accorded a position among the Polypes, near Alcyonium, which represents the latter's _Polypiers empates_; and it is interesting to notice that, for many years remaining among the Protozoa, meanwhile even by Agassiz regarded as vegetables, they were by Haeckel restored to a position among the Coelenterates, though for over twenty years they have by some American zooelogists been more correctly regarded as a separate phylum.[124] Lamarck also separated the seals and morses from the cetacea.

Adopting his idea, Cuvier referred the seals to an order of carnivora.
Another interesting matter, to which Professor Lacaze-Duthiers has called attention in his interesting letter on p.

77, is the position assigned _Lucernaria_ among his _Radiaires molasses_ near what are now Ctenophora and Medusae, though one would have supposed he would, from its superficial resemblance to polyps, have placed it among the polyps.
To Lamarck we are also indebted for the establishment in 1818 of the molluscan group of Heteropoda.
Lamarck's acuteness is also shown in the fact that, whereas Cuvier placed them among the acephalous molluscs, he did not regard the ascidians as molluscs at all, but places them in a class by themselves under the name of _Tunicata_, following the Sipunculus worms.

Yet he allowed them to remain near the Holothurians (then including Sipunculus) in his group of _Radiaires echinodermes_, between the latter and the Vers.