In 1850 Duchassaing described a genus Actinostella, with A. formosa 

 Duch. as its type, and there seems no room for doubt that this type 

 belongs to the sanie genus as Milne-Edwards' 0. muscosa. If then the 

 fusion of Phyllactis and Oulactis be accepted, it is evidcnt that the 

 rules of priority deraand that the genus so constituted be termed 

 Actinostella. 



In later days other genera have been added to the famity, such 

 as Lophactis and Asteraotis (Verri li, 1869), Diplactis (McMurrich 1889a), 

 Cradaetis (McMurrich, 1893) and Phyllodiscus (Kwietniewski, 1898), 

 and a few words may be said as to the validity of each of these. 



And first of ali it may be stated that Diplactis is in ali probability 

 not a Phyllactid at ali, but an Actinid, Verrill's suggestion (1899) that 

 the type D. bérmudensis is an Actinia being well made. Phyllodiscus, 

 too, seems hardly referable to the family, the distribution of the short 

 branched processes over the greater part of the column wall and the 

 practical absence of a sphincter being hardly consonant with the 

 characteristics of the Phyllactids, and I ani inclined to agree with 

 Haddon (1898) and Carlgreu (1899) that it is more properly referable 

 to the jMiciidae. There remain, then, for consideration Verrill ' s two 

 genera and Cradaetis. 



It would seem that Lophactis may owe its existence to the mis- 

 conception of the true nature of the fronds of Phyllactis, already re- 

 ferred to, and, granting the existence of verruca^ in the latter genus, 

 it would appear that Lophactis is identical with it and should conse- 

 quently be included in the genus Actinostella. Similarly there seem 

 to be no very good reasons for regarding Asteractis as distinct from 

 Actinosella; indeed Verrill himself (1899), by including .4. formosa in 

 his genus practically admits the identity of Asteractis and Actinostella, 

 although he ignores the priority of Duchassaing's name. 



As for Cradaetis it seem to me that its clumps of small, dichoto- 

 mously branched acrorhagal processes are entitled to generic value, 

 as contrasting with the broad tuberculate and cichoraceous fronds of 

 Actinostella and as formi ng an interesting transition between the 

 fronds of the latter genus and the compound acrorhagi of such a 

 Cribrinid as Anthopleura. There is no doubt that the Phyllactids are 

 closely related to the Cribrinids, in fact the separation of the two 

 families is little more than a taxonomic convenience and it seems ad- 

 visable to extend our regard for convenience to the recognition of this 

 to a certain extent transitional genus. 



Genus Actinostella Duch. 



Synon : Actinia (pars) Lesueur, 1817. 

 Metridium (pars) Dana, 1846. 



