OF POLYPES. 
31 
portion of zoophytes hitherto considered legitimate subjects of 
their order to the mollusca, which, about the year 1815,* had 
received a considerable accession to its numbers from the same 
source ; but so far from acknowledging the propriety of the pro- 
posed translation, I incline to agree with Lamarckf, that it would 
be better to separate again the colonized zoophytes from the 
mollusca, and form with them, and with such zoophytes as have 
an analogous organization, a distinct class, to occupy the wide 
interval between the molluscan and radiated types, allied to the 
former by the non-symmetrical figure of the body, and to the 
latter by the circularity of the oral members. It is, however, 
unnecessary to enter here upon this discussion, for my intention 
is to describe what are usually reckoned zoophytes, without 
having regard to the naturalness of the group considered as a 
whole, and with this view I adopt the class as it was long ago 
established by Solander and Ellis, excepting only the corallines 
and sponges, which will form the subject of separate monographs. 
The following definition may serve to characterize the class : 
Animals avertebrate , inarticulate , soft , irritable and contrac- 
tile , without a vascular or separate respiratory or nervous sys- 
tem : mouth superior , central , circular , edentulous , surrounded by 
tubular or more commonly by filiform tentacula : alimentary ca- 
nal variable , — where there is an intestine the anus opens near 
the mouth: asexual ; gemmiparous : aquatic . — The individuals 
(Polypes) of a few families are separate and perfect in themselves , 
but the greater number of zoophijtes are compound beings , viz. 
each zoophyte consists of an indefinite number of individuals or 
polypes organically connected and placed in a calcareous , horny 
or membranous case or cells , forming , by their aggregation , 
corals or plant-like Polypidoms. 
In this definition there are two parts which require our par- 
ticular attention — the Polype whose presence is essential, and 
the Polypidom,X which is the house or support of the polype, 
* Savigny’s Memoires sur les Animaux sans Vertebres. Seconde Partie. Pa- 
ris, 1816, 8vo. 
| Hist. Nat. des Anim. s. Vert. iii. 82 — 87. 
\ I borrow this term from the translator of Lamouroux’s work on Corallines. 
The Rev. Mr Kirby, in his Bridgewater Treatise, uses the word Polypary to ex- 
press the same thing. Both of them are translations of Polypier , a word in- 
vented by Reaumur, and now in general use among the French naturalists. 
