256 ZOOPHYTES. 



the water, while two feathers, issuing from below, stretch during its 

 ascent to an immoderate length, one side of each being meagrely furnish- 

 ed with cilia, fig. 5 ; fig. 6, the same slightly enlarged. 



Now it becomes a very interesting object. Rising always higher and 

 higher, until its globular body reaching the surface of the water, it is found 

 impossible to get farther, its course is reversed ; first shortening its long 

 appendages, they continue to be gradually contracted, until becoming in- 

 visible. Such motions, ascent, extension, and contraction are constantly 

 operating, so as to be a very amusing sight. 



But confinement impairs the creature's activity. Instead of seeking 

 the surface, according to its natural habits, it remains at the bottom of 

 whatever vessel ; the cilia of the ribs are yet in motion, while the appen- 

 dages extend no more. Heat and light stimulate attempts to move ; but 

 the body at length falls to pieces, though the cilia of the fragments are 

 still in action. 



This Beroe is quite transparent. It has eight vertical ciliated shuttle- 

 shaped ribs like those of the others, broadest in the middle, and diminish- 

 ing towards each extremity. The action of the cilia rather seems to be 

 successive as the animal swims, those of one rib striking the water after 

 the cilia of the rib acting before it. 



In proportion to the diameter of the body the appendages are very 

 long. The cilia bordering one side are like themselves extensile, and 

 become very slender. I computed seventy on one of those of fig. 5. Its 

 fellow, originally as long, was accidentally mutilated, when it appeared to 

 me that a considerable portion was reproduced. 



The appendages can extend equal to many diameters of the body. 

 Those of a minute specimen, not exceeding a line in diameter, were shot 

 forth to the surprising extent of two inches, then resembling the finest 

 hairs. 



Motion is chiefly effected and regulated by collapse of the body, and 

 the operation of the cilia. 



These animals are not rare in the summer season. I was indebted to 

 a distinguished naturalist, Professor Edward Forbes, of the London Uni- 

 versity, for four living specimens brought from the coast of Fife. 



