66 CLASS II. 



nearer alliance to Sea-Anemonie-s (Actinia?}, which CHAMISSO and 

 EISENHARDT had properly classed with Polyps 1 , although CUVIER 

 joined them to the Medusae (Aoalepkcs), LAMARCK and SCHWEIGGER 

 to the Star-fishes (Echinodermata) . These Actinice have a tubular 

 form, or resemble truncated cones. By their discoidal base they 

 adhere to rocks, marine shells, and other bodies ; but are able to 

 loosen their hold, and to consign themselves to the motions of the 

 water. They can also creep by means of that base, as the belly- 

 footed molluscs ( Gasteropoda] do by means of their ventral disc. 

 But ordinarily the motions of these animals are restricted to a 

 greater or less expansion of the oral aperture, and to a contraction 

 of the hollow tentacles which surround the mouth in a variable 

 number, but always greater than twelve. These Actiniae are naked 

 Polyps, rather of a coriaceous than a gelatinous consistence ; they 

 were not unknown to the ancients, and are noticed by ARISTOTLE 2 

 as Acalephce, and by PLINY 3 as Urticce. Such Polyps with Polyp- 

 stocks are the genera Fungia, Caryophylla, Astroea, Mceandrina. 

 The Polyps of other Polyparies, as Isis, Alcyonium (Lobularia), 

 Tubipora, &c. have eight tentacles, which are flat and notched on 

 the edges or have lateral prolongations. In all these the intestinal 

 canal is a blind sac. But there are other Polyps which, by their 

 more perfect organisation, approach the Molluscs. Their intestinal 

 canal is reflected upwards, and terminates by an opening close to 

 the mouth. AUDOUIN and MILNE EDWARDS observed this struc- 

 ture (1828) in Polyps of the genus Flustra*: at the same time 

 EHRENBERG published his earlier observations to the same effect, 

 and gave to Polyps, with this organisation, the name of Bryozoa; 

 which has been received into the systematic works of zoologists 5 , 



1 Nov. Act. Acad. Ccesar. Leop. Carol. Natur. Curiosor. x. p. 354, 355. 



2 "E0Tt 8 Kal rb r&v aKa\r)<t)U)v yfros tdiov ' irpocnrtipvKe ok rais irfrpais, wa-irep Zvia 

 T&V 6o-Tpa.Ko8tpfJi.uv ' ajroXverai d' More. OVK x.t 5t o<?Tpa.KOv, &\\a <ra/)KcD5es Trav 

 tan? avrov, K.T.\. De Anim. Hist. IV. c. 6. These words, in my opinion, apply to 

 Actiniae alone. 



3 Hist. Nat. Lib. ix. c. 68. But that Medusce also (our Acalephce) were by the 

 ancients designated under this name, I will by no means deny. 



4 Resume des recherches sur les Animaux sans Vertebres faites aux Ues Chausey, Ann. 

 des Sc. not. Tom. xv. 1828. pp. 12, 13. 



5 Symbolce physicce sen 2 cones et Descriptiones Animalium evertebratorum ex itinere 

 F. G. HEMPBICH et C. G. EHEENBEBG, Dec. I. Berolini, 1828. folio. Polypi, p. 2. Also 



