Natural History of British Zoophytes. 447 
mouroux and Lamarck entertained a very different opinion. The 
former,, with feigned regret of the hopelessness of an anatomical 
method, and with a conviction of its inapplicability if attained, pro- 
ceeded to arrange and subdivide the class on the ground of differ- 
ences in the chemical composition of the polypidoms; and the latter, 
assuming that their cells and corals were an exact cast or mould of 
the features of the polypes, and hence that a sameness in the struc- 
ture and form of the one necessarily implied a correspondency in the 
structure of the other, invented a system which he has, with a com- 
placency that is almost ludicrous, pronounced to be in exact harmony 
with the march of nature in her creations, or, to use a language more 
becoming us, with that plan upon which the Author of Nature has 
apparently proceeded in calling his creatures into existence. We 
shall analyze these systems hereafter : it is at present sufficient to 
say, that the result of their labours has been a very preposterous 
combination of species and genera, separating, in many cases, what 
is nearly affined, and, in other instances, assorting together what are 
most alien. There is indeed no safer course for the systematist than 
that pointed out more especially by Blainville : the anatomy of the 
polypes must be the basis of his primary divisions, while in the com- 
position of the polypidoms he may possibly find characters to discri- 
minate and circumscribe the secondary groups in the absence of that 
more certain knowledge which the comparative anatomist has yet 
failed to give him. On this principle we now attempt to classify 
the British Zoophytes, which it is proposed to divide, in the first 
place, into the following sub-classes and orders. * 
Sub-class I. RADIATED ZOOPHYTES. 
Body contractile in every part, symmetrical ; mouth and anus one ; 
always gemmiparous ? 
Order I. HYDBOIDA. Polypes compound, rarely single and naked, 
the mouth encircled withroughish filiform tentacula; stomach with- 
out proper parietes ; intestine ; anus ; reproductive gemmules 
pullulating from the body and naked, or contained in external ve- 
sicles. Polypidoms horny, fistular, .more or less phytoidal, fixed, 
external. Marine, excepting Hydra, which is lacustrine. 
Order II. ASTEROIDA. Polypes compound, the mouth encircled 
with 8 fringed tentacula ; stomach membranous, with dependant 
vasculiform appendages ; intestine ; anus ; reproductive gem- 
mules produced interiorly. Polype-mass variable in form, free or 
* The classification indicated by Audouin and Milne- Edwards seems in exact 
harmony with the one here adopted. Recherches pourservir a 1'Histoire Nat. 
du Littoral de la France, Vol. i. p. 73 6- 
