A monograph of the British fossil corals - kreidefossilien.de

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BRITISH FOSSIL CORALS.
CLASSIFICATION
OF POLYPI.
Sub-kingdom ZOOPHYTA; Section RADIATA.
Class
POLYPI.
Animals of the sub-kingdom of Zoophyta, and of the section of Radiata,^ organized
for a sedentary mode of Ufe, having no locomotive organs, and being provided with a circle of
retractile tentaculas around the mouth, and a central gastric cavity, not communicating with
an anus, and containing the reproductive organs when these exist ; in general fissiparous,
or multiplying by buds as well as by ovules.
The systems adopted by Cuvier, Lamarck, Lamouroux, and their contemporaries, for the
subdivision of the class of Polypi, were founded on external characters of very little value,
and were quite artificial. In a Memoir, pubhshed about twenty years ago," a first attempt
was made to establish this classification on anatomical facts, and the Zoophytes presenting
the above-mentioned structure were distributed in two groups, characterised by the presence
or the absence of internal ovaria, and a membranaceous tube leading from the mouth
to the great gastric cavity. Subsequent observations have coufrrmed these views, and
Mr. Dana, whose recent work^ is one of the most valuable contributions which America has
yet made to Natural History, divides in a similar manner the class of Polypi into two
secondary groups. We shall continue adopting this classification here ; but the name of
Adinoidea, which Mr. Dana applies to the first of the two sub-classes thus estabhshed,
having been previously enqiloyed by other zoologists in a much narrower acceptation, we
have thought it advisable not to make use of it here, and we propose substituting for it that
of Corallaria. The second group comprises the Sertularian Polypi (Milne Edw.), and may
be designated by the name of Hydraria.
1 The sub-kingdom of Zoophytes may be divided into two natural groups : the one comprising all the
true Radiate animals (Echiuoderma, Acalephse, and Polypi) ; the other containing the spheroidal or amorphous
Zoophytes (such as Spongidse and certain Infusoria). The first may retain the name of Radiata
the second has been designated by that of Sarcodaria (Milne Edwards, Cours glementaire de Zoologie).
2 Recherches sur les Animau.x sans Vertebres, faites aux iles Chausay, par MM. Audouin et Milne
Edwards (Annales des Sciences Naturelles, premiere serie, t. xv, p. 18, Septembre, 1828).
3 United States Exploring Expedition ; Zoophytes. Philadelphia, 1846.