THE TENTACLES. 20 



arranged in about six rows ; the innermost series con- 

 tains about twelve tentacles ; the next about the same 

 number ; the third about twice as many ; the fourth 

 is ag-ain doubled ; the fifth increases in the same pro- 

 portion, and the sixth contains about thrice as many 

 as the fifth. This ratio, if accurately carried out, 

 would give a total of seven hundred and sixty eight 

 tentacles to one Actinia, a number which is not far 

 from the mark, though as in other species, the rows 

 are not quite regular. The inmost series of tentacles 

 is usually erect, or even inclines inwards, the others 

 decline more and more towards the circumference, 

 until the outmost two or three rows lie quite flat upon 

 the disk, to which the exterior one of all forms an 

 exquisite fringe ; all the rows are small, but they 

 diminish outwardly in size, and more rapidly the 

 nearer they approach the edge ; those of the outmost 

 row are very minute, the longest (for they are not 

 equal) not exceeding the sixteenth of an inch in length, 

 and some being only tiny tubercles : they are slender, 

 and set so close together, that I counted sixty in 

 an inch. 



The mouth is oblong, sometimes contracted to a 

 slit, at others showing a sub-oval, or lozenge-shaped 

 opening, with the lips within finely crenated. Deli- 

 cate depressed lines diverge from the mouth to the 

 circumference of the disk, by tracing which we shall 

 find that the convex space included between two lines 

 leads to and terminates in a tentacle ; the disk may 

 in fact be described as formed of the roots of the ten- 

 tacles soldered together. Viewed from outside, with 

 a strong light behind, the substance of the disk is 



