ACTINIA. 227 



§ 5. Actinia explorator. — The Searching Actinia. — Plate XL VI. 

 Fig. 11. — The aspect of individuals belonging to the same species of the 

 Actinia, is diversified in such an extraordinary manner, as at one time in- 

 duced me to conjecture, that, notwithstanding the colour and dimensions 

 of the present subject, it might be a variety of the last, the Actinia elegans. 

 But nothing has corroborated the fact ; neither can I identify it with pre- 

 ceding descriptions. 



In as far as I have observed, the Actinia explorator is entirely litto- 

 ral, — dwelling chiefly in the crevices of rocks, covered by the flowing tide, 

 or protected among stones which are not likely to be disturbed. 



The largest specimens rise about two inches high, and expand nearly 

 as much between the opposite tips of the tentacula, which are about half 

 an inch long, and disposed in a triple row. The body is quite smooth. 

 Both it and the base are dingy white : the disc mottled grey, produced by 

 the alternation of lighter and darker ellipses, in singular and beautiful ar- 

 rangement ; and the tentacula are belted with black. — Plate XLVI. 

 fig. 11. 



Probably this animal is of various shades, from dingy white to liver- 

 brown, at least I have been led to associate it with specimens found in 

 different parts of the Scotish seas. Some of these were sent to me from 

 the west, by Sir Walter C. Trevelyan, Baronet, a gentleman much and 

 usefully devoted to literary and scientific pursuits. 



A remarkable property of this species is the spontaneous enlargement 

 of one or more of the tentacula to an immoderate size above the rest, such 

 as I have not observed incidental to any other of the tribe. The first 

 time it occurred being at night, I conjectured that either some unusual 

 organ was protruding, or that a worm was involved among the tentacula — 

 both alike improbable. Several years afterwards, the fact was confirmed 

 by new observations. 



A small specimen, not exceeding half an inch in diameter, exhibited 

 .two tentacula, both enlarged at once to an inch and three quarters in 

 length, whereas the tentacula of the largest specimens do not extend 

 above one-third as much, in their natural proportions. 



During this state, the tentacula are extremely flexible, waving from 



