866 THE RED-LTNED CHRYSAORA. 



by a tubular fold of the common pellucid membrane, 

 which extends to about double its length. (See fig. 

 2). On crushing one of these eyes with graduated 

 pressure beneath the microscope, it was most interes- 

 ting to find its substance entirely composed (so far 

 as I could perceive) of an infinite multitude of regu- 

 lar colourless crystals, the greater number of which 

 were short six-sided j)ris7ns, and, as I thought, with 

 convex extremities. (See fig. 3). Of this latter 

 point, however, I am not quite sure ; but their hex- 

 agonal form was perfectly distinct ; and I could not 

 but conclude these to be true visual lenses, perhaps 

 as perfect as those of Crustacea or Insects. Their 

 diameter was about TTT^T^th of an inch. 



1500 



The sub-umbrella agrees in general form with the 

 umbrella, but is much more depressed. From its cen- 

 tre depends an ample globose peduncle, which after 

 being constricted, terminates in four membranous 

 arms of excessive delicacy and beauty. Each arm 

 consists of a cylindrical, or rather insensibly tapering, 

 process, resembling a tentacle in length and slender- 

 ness. All along one side of this filament is attached 

 a ribbon of pellucid membrane, more delicate than the 

 finest cambric : it is upwards of an inch wide above, 

 but gradually tapers to a point ; and is so attached by 

 one of its edges to the filament, as to fall into ample 

 folds or furbelows, exactly like the flounces of a 

 muslin dress. The grace and beauty which these 

 appendages impart to the animal can scarcely be 

 imagined, by those who have not witnessed a similar 

 spectacle. Sometimes, indeeed, they are contracted 

 into a shapeless mass, only two or three inches in 



