234 CHAS. L. WALTON. 



the green with purple-tipped tentacles, and the brown and grey. 

 Both these are most abundant, frequently inhabiting the same pool. 

 The species is provided with very powerful sting cells (I have myself 

 been well " nettled " when handling large specimens) and is evidently 

 sufficiently protected from fish attacks, or at any rate to a considerable 

 extent. Both varieties when under water present a decided resem- 

 blance to masses of Algae, and doubtless obtain much food in the form 

 of deluded Crustacea, and I am inclined to consider the colouration as 

 partially aggressive, with secondary warning colours in the purple tips 

 of the tentacles, and the occasional scarlet area on the lower portion of 

 those organs. It is to be noted that these characters usually only 

 accompany the green variety named sinaragdina by Gosse. The scarlet 

 area on the tentacles is mentioned by Gosse (p. 162) as occurring at 

 Herm, and I have seen it in varying degrees on several occasions. I 

 will give one instance from my notes. Near low- water level at 

 Polzeath (N. Cornwall) I came across two enormous individuals 

 attached side by side. The columns were rich purple-brown, the 

 tentacles some four or five inches in length, a most vivid green, 

 and purple-tipped, while the bases of the tentacles resembled flame- 

 coloured silk. I touched them with my finger, knowing that irritation 

 usually produces an increase of brilliance in this species ; the tentacles 

 at once bent inward, thus exposing the lustrous, glowing areas to 

 plainer view. F. G. A. Stuckey in his Review of Neiv Zealand 

 Adiniara says of Anemonia olivacca, Hutton : " This species is found 

 in rock pools, often inhabiting quite small pot holes on the upper part 

 of the rocks. Its colour is strongly protective." I have examined 

 numbers on the west coast of the N. Island, and consider that this 

 also is a case of " aggressive " colouration, as it greatly resembles tufts 

 of green Algac. 



I had frequently noted in many Sagartids that in some specimens 

 the acontia would be emitted on the slightest provocation, while in 

 others they were only protruded after severe irritation. I now regard 

 this as largely due to varying environmental conditions. Those indi- 

 viduals which have been exposed to constant friction only emit the 

 acontia after considerable irritation, whilst those which have been 

 living in quiet and undisturbed surroundings emit the acontia with 

 freedom and at the least touch. My reference to constant friction 

 applies to individuals which, living within tide marks, are exposed to 

 constant boil of surf, causing abrasion by shingle, etc., or constantly 

 brushed by Algae. 



- This control of acontia is closely connected with and analogous to 

 the control of nematocysts, etc., referred to in a former paper (" Notes 



