124 ACTINLE OF AL1?ATR<^SS FAPLOKATIONS M'RIURRICH. 



t'lassilioation tbuiul in lator authors. Tlic la rye iminbei' of forms 

 brouylit to iiotico by tlu> soientiiu' voyages of tliis poriod incroased 

 noticeably llic imiiibcr of Aotiniau .noiiera, and in llic classitications of 

 Dc lilainvillo and l^lirt'idxM'u' we find a considcrablo nnnibiT of ^"euera 

 establisliod. 



Attention has already Ixhmi calli'd to the discovery of the Aetinian 

 eharaeter of Ccrittiitlnis by liapp ('!'!>), the siil>s(M|nent a|»i)lieation of 

 tiiei;enene name by which it is now known l)y Delia Chiaje. in 1811 

 Qiiatretai>es (Ml), in a i)aper which is a model of accurate observation 

 and description, established the u'enus fj(lir<()-<lsi(( on essentially the 

 same basis as that on which it now rests, tlionuh nioi'e recent obser- 

 vations have added certain particulais winch the methods of micro 

 seopie iuvesti.uation of the da.\ have brought to liuht. 



The year ISll marks therefore tlu' establislnnent of most of the groups 

 of Aetinaria which are now reco.«iiii/ed, so far as they possessed generic 

 value, but tor some time CcridiifliKs and l-Mirdrdsid were considered of 

 equal taxouonde value with Actinia, Tltal<(.ssi<(ittht(s, hiscosohKi, and 

 other simjdy generic terms. The Zoanthun group formed to some extent, 

 however, an exee])tion to this rule, probably on account of their colonial 

 habit of life and the power some i>ossessed {Pali/tluxi, Ctrticifvnt) of 

 encrusting themselves with calcareous or siliceous particles, recalliug 

 by their consistency skeletogenous forms. Their gemmijiarous repro- 

 duction indnced Dana to group them apart from the rest of the Actin- 

 ians, and associate them with the Oaryophyllid corals. 



To give aresunu' then of the state of Anthozoan taxonomy at the 

 middle of this century it may be said that the grouj) was delinitely 

 delimited, the liryozoa having been excluded in accordance with the 

 observations of Milne Edwards. The Alcyonarian forms had been 

 grouped together from their earlier separation iato a nuud)er of groups 

 each equivalent to the llexacorallia. Actinia', etc. The Antipatharia 

 were referred to the Authozoa, and even constituted a group of slightly 

 less value than the Alcyonaria. And lastly, the Actinia' had been 

 divided into a number of genera and associated with the Ilexacin-allia, 

 the similarity of structure of the aniuuUs themselves being considered 

 of greater nu)ment than the possession or absence of a corallum. 



A new era in Anthozoan classilicatiou was introduced by the publi 

 cation in ISoT of the lirst two volumes of Milne-Hd wards' Jlistttirc 

 udtiircllc (h's ConiUidircs. In some respects, notably in the severance 

 of the .AIadr(>poi'es from the Actinians. a backward step was taken 

 wliich has been maintained up to a conq)aratively recent date, but on 

 the other hand, a decided advance was accomi)lished in tlu' more accu- 

 rate delimitation of several groups, and in the recognition of groups of 

 genera among the Actinians. 



Milne-Edwai-ds recognized Leuekart's division of the Cuvierian lladi- 

 ata into the two gr(mi)s I'A'hinodermata and Coelenterata, and divided 

 the latter into two classes, the Acalephs, including three sub-classes, 



