ZOOPHYTES. 391 



tended from the creeping root, some of wliich stand np 

 freely in the water, with their knobbed extremities 

 floating in the wave. 



This is one of the Polype tribe, named Staii/ridia 

 prodticta, and as its form and structure are interesting, 

 we will devote a few moments to its examination. 

 We can easily sever one or two of the freely floating 

 threads, and transfer the amputated portions to one of 

 the live-boxes of the microscope. The motions and ap- 

 pearance of the club with its organs will be, for a 

 while, little aflfected by the violence. 



The long cylindrical thread is enveloped in a trans- 

 parent horny tube, which, however, so closely invests 

 it, that it is with difficulty distinguished. Tlie club- 

 shaped head, or individual polype, is an enlargement 

 of the thread, which protrudes from the investing tube. 

 It is swollen in the middle and rounded at the end, and 

 many of the heads, which ai'e more ventricose than the 

 rest, contain a bubble of air in the centre. This air is 

 doubtless taken in at the mouth, which is situated at 

 the extremity ; for, though you' can discern no perfora- 

 tion, yet there is an aperture capable of being opened 

 widely at the pleasure of the animal, and surrounded 

 by protrusile, contractile, and expansile fleshy lips. 

 I have several times seen this mouth opened, and 

 partly everted, in kindred species ; and once I had 

 an opportunity of witnessing a quite unexpected xise to 

 which it was applied, viz. that of a great sucking disk. 

 T had put the animal in such a live-box as this — the 

 two glass surfaces being just sufficiently wide apart to 

 allow it free liberty to turn about in all directions as far 

 as it wished. On my looking at it after a momentary 

 interval, I saw that the extremity had suddenly be- 



