at 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. He differs from Cuvier in regarding the tunic as the homologue of
the shell of Lamellibranches, remarking that it differs in being
muscular and contractile.

Lamarck's fame as a zooelogist rests chiefly on this great work. It
elicited the highest praise from his contemporaries. Besides containing
the innovations made in the classification of the animal kingdom, which
he had published in previous works, it was a summary of all which was
then known of the invertebrate classes, thus forming a most convenient
hand-book, since it mentioned all the known genera and all the known
species except those of the insects, of which only the types are
mentioned. It passed through two editions, and still is not without
value to the working systematist.

In his _Histoire des Progres des Sciences naturelles_ Cuvier does it
justice. Referring to the earlier volume, he states that "it has
extended immensely the knowledge, especially by a new distribution, of
the shelled molluscs ... M. de Lamarck has established with as much
care as sagacity the genera of shells." Again he says, in noticing the
three first volumes: "The great detail into which M. de Lamarck has
entered, the new species he has described, renders his work very
valuable to naturalists, and renders most desirable its prompt
continuation, especially from the knowledge we have of means which this
experienced professor possesses to carry to a high degree of perfection
the enumeration which he will give us of the shells" (_Oeuvres
completes de Buffon_, 1828, t. 31, p. 354).

"His excellences," says Cleland, speaking of Lamarck as a scientific
observer, "were width of scope, fertility of ideas, and a preeminent
faculty of precise description, arising not only from a singularly terse
style, but from a clear insight i