324 ZOOLOGY, 



slightly united to each other, but are more firmly at- 

 tached to a soft white cord that passes through the 

 centre and entire length of the perfect animal. When 

 removed from the water, this medusa displays spon- 

 taneously^ and from its whole -surface, a vivid phosphoric 

 light, little inferior to that of Pyrosoma; and when 

 agitated in fresh water, it communicates to that fluid 

 a multitude of scintillating particles, which emit a very 

 white gleam. We found many distinct varieties or 

 species of this medusa. They differ in size and form : 

 some being eight inches in circumference by three in 

 length, and nearly cylindrical in form ; while their 

 aggregate portions, all uniform in shape, are pyramidal, 

 and present four facets. Others are globular, and re- 

 semble a mulberry. But they all agree in possessing a 

 curious resemblance to crystals, both in their entire 

 form and in the shape of their component parts, and 

 have the same highly luminous properties. 



A. third luminous medusa, which we obtained in lat. 

 40 N., long. 142 \y. ? i s about one inch in length, and 

 shaped like an open bag, or landing-net, its one ex- 

 tremity being a wide circular orifice, while the opposite 

 is rounded and closed; its gelatinous structure is 

 enveloped in a smooth membrane or tunic. The inte- 

 rior of the body is one capacious cavity, or sack ; its 

 bottom occupied by a fringed structure, of a pink colour ; 

 numerous short slender tentacles are attached to the 

 border of the circular orifice ; and the upper surface of 

 the same border, which is somewhat broad and thick, 

 is provided with a single row of small red tubercles, 

 which, as well as the entire body of the creature, emit 

 in the dark a very bright phosphorescent gleam. This 

 species does not communicate any luminous matter to 

 either fluids or solids in contact with it. Upon more 



