MISCELLANEOUS. 249 



This specimen bore considerable resemblance to a small thimble or 

 Chinese bell, nearly half an inch in diameter, rather more in height, and 

 in shape forming above half an ovoid. Owing to the thickness of the 

 transparent gelatinous substance of the upper part, it seemed a double 

 bell, or one bell covering another, which, I apprehend, is from the upper 

 and the under surface being a little darker than the matter between them. 

 Four equidistant tentacular organs, of extraordinary length, extending not 

 less than six inches, descended from four knobs, each with a black speck on 

 the edge of the bell. The microscope shews their curious structure, that 

 they are as if composed of three united warts, each with a convex edge, 

 which is furnished with a row of strong black bristles. These compound 

 enlargements are set at intervals on the tentaculum, near its lower ex- 

 tremity. But this apparatus can be seen only when the animal is too 

 weak to traverse the water. A long proboscidal organ descends from the 

 centre of the concavity of the bell, dilating at the extremity. 



The circulation of a fluid through channels of the bell, is discovered 

 by the descent of dark particles from above. 



This animal is extremely transparent : it is often difficult to be dis- 

 cerned amidst the water. Motion results from jerks, or leaps produced 

 by collapse of the body. The tentacula extend as the Medusa rises and 

 falls, or remains stationary. 



Plate LIII. Fig. 1. Medusa proboscidea. Body, a ; tentacula, b ; proboscis, c. 



(B.) The variable figure of the umbrella, and indeed of the whole 

 other parts peculiar to the Medusarian race, tends greatly to embarrass our 

 discrimination of the different species. 



Animals which, if not to be identified with the former, stand in im- 

 mediate kindred to it, have occurred on several occasions, in May and 

 June. The largest were about five lines in diameter and six in height, 

 and forming a considerable portion of a sphere or of an ovoid. In such 

 specimens, the proboscis extends completely two inches, and the tentacula 

 three. But it is impossible to assume what may be the extreme dimen- 

 sions of such ductile parts. The tentacula contracted, Plate LII. 

 VOL. II. 2 I 



