with descriptions of several of the objects which cause it. 433 



in the luminosity of the sea, being present in swarms. They 

 differ from the naked-eyed medusse in having the stomach ex- 

 ternal on the upper part of the umbrella. They are brilliant 

 fellows, and flap and snap their cilia about, and at times throw 

 them up as at fig. 1 a ; this position appears to be a state of rest. 

 Fig. 1 b. shows the stomach highly magnified ; fig. 1 c, ditto 

 with the lips turned down ; 1 d, the arrangement of the tentacula ; 

 3 a, the stomach of fig. 3 : this sort is not so common, and has 

 the stomach also on the upper side of the umbrella ; I fancy they 

 maij be the gemmse of Corallines. 



I now pass to fig. 4, another of the class Diphydia, but of a 

 different shape ; these occurred several times ; the outer part is 

 glass-like, shaped like a wine-glass without a foot, the internal 

 part granular and yellow, the widest part surrounded by pointed 

 delicate ciha, by which it moved in the most rapid manner, 

 darting about, across and up and down ; at times it would rest 

 on the sharp point, and turn round like a boy's top when it 

 makes the last gyrations before falling, the upper part describing 

 wide circles ; this it would continue for some time, then fall down, 

 withdraw its cilia and lie on its side as if to rest ; all at once it 

 would rise and dart off on its gambols again. It very much 

 resembles the Cubiodes vitreus, fig. 3892, page 421, of Knight's 

 'Museum of Animated Nature,' also figured in the 'Penny 

 Cyclopsedia,' found in the Straits of Gibraltar, where it appears 

 to have a case and live in groups. These had no case and 

 were solitary; in every other respect they were like the one 

 from Gibraltar. Fig. 5 is a much smaller specimen; it is 

 wholly granular, still yellow, and the mouth surrounded with 

 cilia, moves quickly, generally with the ciha downwards; it 

 greatly resembled the seed of the sweet scabious, and pro- 

 bably may be the young of the other. Minute as it was, the 

 "interjections," though represented so large at fig. 6, were para- 

 sitical upon the former ; these put down their disk-like foot, then 

 turned over their rounded head, and threw a summerset, recovered 

 themselves and repeated it again and again ; and upon these para- 

 sites I observed their parasites, fig. 7, minute indeed, and which 

 I believe were Cypris in various stages of growth. 



Fig. 8 is a strange thing, evidently one in a state of trans- 

 ition, lies on its side, and runs round by jerks like the seconds 

 hand of a clock when the pendulum is taken off. When tired, 

 it closes up and assumes the form of fig. 8 a. The head part is 

 dark and granular, the wing-like appendages glassy and brilliant. 



Fig. 9, no doubt one of the same kind, found a few days after, 

 further advanced. 



Fig. 10, the tadpole of one of the Botrylli, probably Cynthia ; 

 it was beautiful, and appeared to be moored by a very delicate 



Ann. ^ Mag. N. Hist. Ser. 2. Vol. vi. 29 



