254 CLASS IV. 



PALYTHOA. 



Polypi DOM in one extended patch, covered with 

 cylindrical protuberances or papillae of more than a 

 centimetre in height, and united to each other ; the 

 cavities or cells insulated, almost longitudinally parti- 

 tioned, and containing only one polypus. 



The Palythoas vary but little in their forms, and 

 exhibit a mass composed of papillous protuberances 

 ^ve or fcix millimetres wide, and from one to one and 

 a half centimetre high; these papillse are united and 

 adhere together almost to their extremity, which is 

 round, and pierced at the centre so as to allow the 

 issue of the polypus. It is not improbable but that 

 this opening may be the mouth of the animal ; which 

 is contained in a large cell, having its partitions 

 marked with projecting and longitudinal laminae, the 

 number of which I have not been able to ascertain. 

 The colour is an earthy grey. Such are the principal 

 characters of the dried Palythoas. In the living state, 

 that earthy colour does not exist, but brilliant hues 

 then adorn this animated mass ; for I do not look 

 upon these papillae as inert cells into which the po- 

 lypi retire, but as forming part of the animal itself, 

 as far more necessary, and far more connected with 

 its existence, than are the shells of many testaceous 

 MoUuscas with theirs. 



These Polypidoms, scarce in the collections, are 

 found in the Antilles. 



