MR. GOSSE ON PEACHIA HASTATA. 271 



culis paucis, brevibus (disci diametrum haud superantibus), crassis, conicis, uni- 

 seriatis ; oviductu in tuberculum papillosum desinente. 



1. Peachia hastata (Gosse), corpore roseo lineis aequalibus pallidis, tentaculis 12 albo- 

 hyalinis seriebus 2 parallelis macularum sagittatarum brunnearum notatis, disco 

 circulis duobus macularum brunnearum V-formium cincto, oviductus papillis nume- 

 rosis aggregatis. 



2 ?. Peachia ? chrysanthelltjm, corpore cylindrico albido lineis insequaliter latis, ten- 

 taculis brunneo annulatis. 



Actinia chrysanthellum, Peach. 



Tbe principal interest of this form is the decided approach which it makes to a higher 

 type of existence than that of the Actinodermata. The sensitiveness to alarm, and the 

 spring-like rapidity of its motions, indicate a greater condensation in the nervous and 

 muscular systems; but the existence of a posterior opening to the digestive canal is a 

 still more decisive advance in structural rank. The approach to the Echinodermata, 

 through the Sipunculidce, is marked, not only by this important character, but also by 

 form, by the degeneration of the tentacles in number and dimensions, and by the 

 tendency to break up the body by spontaneous constriction. 



The genus Edwardsia of M. Quatrefages, still further diminishes the interval between 

 the Actiniae and the Holothurice ; for the mouth and tentacula are, in that genus, seated 

 at the end of a delicate column, which is retractile within the coriaceous trunk, as it is 

 in Syrinx nudus ; and the balloon-like inflation at the posterior extremity reminds us of 

 the same animal. It is curious to trace also, in Syrinx itself, an approach to the 

 Actinoderm type, in the digestive canal terminating near the head, the greater portion of 

 the body being imperforate. 



I may observe, in passing, that the genus Edwardsia is represented by two British 

 species. One was described and figured by myself in the " Annals of Natural History " for 

 Sept. 1853, under the name of Scolanthus callimorphus ; but, as I am now convinced that 

 notwithstanding the apparently simple posterior extremity in that species, it must be 

 referred to Edwardsia, the genus Scolanthus must be cancelled. The name will hence 

 become Edwardsia callimorpha. Another species is described by Mr. Kingsley (in litt.), 

 which appears to be E. Beautempsii of M. Quatrefages. 



I will embrace this opportunity of making a few observations on the more typical 

 Actinice. Restricted as is the genus Actinia, by the separation from it of Adamsia and 

 Anthea among British, of Metridiwm and Actinecta, and many others among exotic 

 species, and by the creation of such genera as Capnea, Corynactis, Ilyanthus, &c, it is 

 still so immense a group, that any subdivision of it on sound principles is desirable, 

 especially when we consider the great difficulty of defining species in this tribe. Indeed, 

 I hold that, wherever we find several characters co-existent in a certain number of species, 

 none of which are common to other species, the species possessing such characters ought 

 to be elevated to the rank of a separate genus. 



Applying these principles to the group before us, I find a number of Actinice, which 



