132 THE AQUARIAN NATURALIST. 



At first, says Sir J. Dalyell, I could scarcely credit 

 the truth of so unusual an occurrence, presenting such 

 a remarkable deviation from the nature of the pro- 

 geny discharged by the vesicles of the various Sertu- 

 larian tribes, but I was unable to recognize any error 

 either in the previous existence of the Medusa within 

 the vesicle, or in its liberation from it. I have since, 

 however, seen the same repeated many times, though 

 at distant intervals. 



When originally observing similar minute Medusae 

 before ascertaining their origin, Sir John Daly ell had 

 no doubt that they were little Acalephae, and had not 

 inaptly bestowed on the young creature the name 

 tintinnabulum, from its resemblance to a hand-bell 

 (PI. II. fig. 5, d). The body in fact might be com- 

 pared to a minute watch-glass, half a line in diameter, 

 bordered by a pendent marginal fringe of about 

 twenty- three tentacula, each of which issues from an 

 enlarged root, and is nearly as long as the diameter 

 of the disc. A central prolongation below corre- 

 sponds to the proboscis of the Medusa, while the ani- 

 mal suspends itself in equilibria in the water; but 

 when reversed, this proboscis appears like a crest upon 

 a convex surface (fig. 5, d) : four lines with enlarged 

 extremities diverge from the base of this proboscis. 

 The animal is whitish, or almost transparent. It 

 swims by jerks, like the various species of Medusae, 

 pursuing all directions, rising, falling, or remaining 

 stationary ; and, like the Medusa bifida, a group of 

 these little creatures closely resembles a flock of mi- 

 nute birds wending their course through the expanse 

 of the firmament. 



