BRITISH ZOOPHYTES. 165 



The noticeable features of the Beadlet are the mar- 

 ginal spherules and basal line, about which much has 

 been written. A summary of previous investigations, 

 together with descriptions of the morphology of these 

 parts, by Prof. P. Martin Duncan, is contained in the 

 Monthly Microscopical Journal, vol. xii. (1874), p. 65. 

 This article is illustrated by descriptive plates, showing 

 fully the structure of the spherules and base. The 

 spherules are held to be a primitive form of eye. 



" The evolution of an eye which can distinguish out- 

 lines, shades, and colours probably took the path 

 which is thus faintly indicated in the Actinia, which 

 doubtless has an appreciation of the difference between 

 light and darkness.^' 



As to the diffused nervous tissue found in the base, 

 probably ^' its function is to assist in the reflex move- 

 ments of the animal, and to produce expansion of the 

 disc on the stimulus of lio^ht." * Professors Hertwig 

 and Dr. Andres, on the conti-ary, consider the sphe- 

 rules as urticating batteries or nematophores.f 



Genus II. Anemonia, Bisso. 



Tentacles long, not retractile. No spherules, acontia, 

 warts, or cinclides. 



1. A. SULCATA, Pennant. "The Opelet.'" 



Actinia viridis {De Bl., Lamh.), A. cereus {U. and 8., 

 Rapp, Oruhe), A. sulcata {Penn., Andres), Anemonia 

 edulis (Bisso), A. sulcata {M. Edw.), Anthea cereus (P. 

 H. G., Hass., G. J., B. B., &c.). 



Hab. : Guernsey (Holds ivorth), Plymouth, Ilfracombe 

 {P.H. G.), Penzance (B. Q. G.), Isle of Man (West), 



• * See also Proceeclings of the Eoyal Society, vol. xxii. No. 151. 

 f " Die Actinien," Professors Hertwig, Jena, 1879. 



