124 POPULAH HISTORY OF THE AQUArJUil. 



with twelve tentacula, whicli are ornamented with arrow- 

 headed brown markings on a white ground ; they are 

 bent outwards and backwards. From the mouth protrudes 

 a fleshy proboscis, the top of which spreads into a ckibbed 

 head, divided into papillae. Mr. Kingsley gives the follow- 

 ing observation on the habits of this Zoophyte : — '' They lie 

 (or rather stand) in wet, ribbed, clean sand, at low-water 

 mark, the disc just out of ground. On digging carefully 

 (for the animal retracts on the least shaking of the sand) 

 vou find that he is buried bolt -upright to the depth of nine 

 inches, where his extremity stops ; the whole animal taper- 

 ing gradually from stem to stern. On being taken out (no 

 easy matter, since its power of retraction, if irritated, is far 

 more springy and rapid than in any of the class, as far as 

 I have tried them), and put into a vase of salt-water, he 

 swells himself out with v\'ater like a Ilolothurian, disclosing 

 longitudinal septa. All his motions are rapid and spasmo- 

 dic ; betokening, as does his whole make, a higher muscular 

 organization than that of the Acti?iiaJ' 



