COELENTEEA. 



IV.-ACTINI^. 



By Joseph A. Clubb, M.Sc. 



(3 Plates.) 



The Actinian collection of the ' Discovery ' Expedition consisted of upwards of fifty 

 specimens, which have been allocated to eight species, representing six genera and four 

 families. With two exceptions, all were taken at or near to the Winter Quarters, 

 McMurdo Bay. The two exceptions * are Port Harris, Falkland Islands, containing 

 two species, and Enderby Island, Auckland Islands, containing one species, and from 

 both places a considerable number of specimens, more than half the total, was obtained. 

 The specimens were for the most part in a fair state of preservation, but I must express 

 regret that no memoranda were made of the colours of the living animals. In the 

 preserved condition absolutely no trace of colour remains, and while admitting that 

 anatomical characters are the only sure guide in Actinological studies, the colours of 

 living Actinians, when known, serve at least as a valuable clue to identification with the 

 species of the older authorities, who give very little but external characters as their 

 diagnoses. 



The work has been carried on in the laboratories of the Liverpool Museums, 

 and I have again to express my thanks to the Museums Committee for permission to 

 use apparatus, etc. , and to Dr. Forbes, the Director of Museums, for other facilities. 



Family ACTINIIDiE, Gosse, 1858. 



AcTiKiARiA with an adherent base ; column wall smooth or provided with verrucse, 

 but never with hollow vesicular outgrowths ; sphincter muscle endodermal, generally 

 diffuse and weak ; tentacles simple ; margin smooth or provided with simple acroragi ; 

 mesenteries in several cycles, of which usually more than one is perfect ; longitudinal 

 muscles of tentacles usually diffuse ; no acontia. 



Genus Parantheopsis, McMurrich. 



Actiniidse without acroragi, but with conspicuous verrucse on the distal portion of 

 the column ; no collar, but the margin a distinct parapet, within which is a well-marked 

 fosse ; tentacles of moderate length and rather slender, capable of being concealed in 

 contraction ; sphincter diffuse. 



* These forms are so interesting that, after some consideration, I have allowed their entrance into this 

 report. — Ed. 



