water. Within an outer transparent dome is an- 

 other dome less arched but equal in diameter with 

 the first and joined to it throughout the extent of 

 the rim. The rim is notched at eight equidistant 

 points, thus dividing the periphery into eight lap- 

 pet-like structures, each lappet bearing a fringe of 

 numerous thread-like tentacles less than a half 

 inch in length. The tentacles are harmless to hu- 

 man touch. In decided contrast with the exceeding 

 transparency of the outer dome, the inner one is 

 opaque and of a bluish milky white. It is marked 

 with numbers of confluent vein-like channels ex- 

 tending radially from the central region at the top 

 — a region which in this animal is distinguished by 

 the most curiously shaped structures of any jelly- 

 fish. These structures are the peculiar horseshoe- 

 shaped gonads, or sex organs. They are four in 

 number, and are placed with their open ends fac- 

 ing the center. It is by these bright-hued and 

 prominent organs that Aurelia may easily be dis- 

 tinguished from all other jellyfishes. 



Now naturalists call this bowl-like part of the 

 jellyfish the "umbrella" ; and it is surely a shape 

 more representative of that homely article than it 

 is of the fancied "disk" with which the earlier 



[360] 



