ZOOPHYTES. 343 



heads as pointing N., E., S., and W., the simple ones 

 point N.E., S.E., S.W., and N.W. 



From the carefully made observations of several excel- 

 lent naturalists, as Dujardin, Steenstrup, Dalyell, Loven, 

 and others, it appears that this beautiful and elegant little 

 Polype gives birth to medusa-shaped young. Contrary, 

 however, to the rule in Laomedea, the Medusa is in this 

 case pushed forth as a bud from the side of the club, 

 without any protecting capsule. The process is exceed- 

 ingly like a plant developing a flower ; for the bud grows 

 until it at length . expands blossom-like, and a beautiful 

 little umbrella-form Medusa is seen adhering to the Polype. 

 At length the brilliant little living flower becomes de- 

 tached ; and, after swimming freely for a time, discharges 

 ova or gemmules from its ovaries, which develop into a 

 creeping root-thread, and finally into the club-headed 

 threads of the Stauridia. 



Some objects which I have to exhibit to you are alto- 

 gether unique as to their appearance ; and, if you are not 

 as imperturbable as a Stoic philosopher or a Mohawk 

 Indian, will certainly excite both your risibility and your 

 wonder. For some little time I have been keeping in this 

 tank a specimen of that rather rare and very interesting 

 Sabella, the Amphitrite vesiculosa of Montagu.* You see 

 it is a worm, inhabiting a sort of skinny tube, much 

 begrimed with mud, about two inches of its length being 

 exposed; the remainder, or about as much more, being 

 concealed among the sand and sediment of the bottom. 



A beautiful object is presented by the gill-fans of this 

 worm. These organs are always elegant, whatever species 

 of the genus is before us ; but here, in addition to the 

 charm of the slender filaments, so delicately fringed with 

 their double comb-like rows of cirri, the tip of each bears 

 a dark purple spherule. That of the anterior filament on 

 each side is much larger than the rest, and forms a stout, 

 * "Linn. Trans.," xi. 19. 



