THE CLUB-BEAraXG MEDUSA. 407 



both in size and numbers. They are pretty uniformly 

 about -^ inch in length, with the linear cavity reach- 

 ing more than fths of the total length. (Fig. 20.) 

 Multitudes are scattered loosely in the mucus that is 

 copiously discharged from the surface, and many 

 appear to be irregularly distributed in the coriaceous 

 tissues ; but others are crowded into groups, whence 

 the threads are projected in dense brushes, to the length 

 of about a line, or thirty-three times that of the 

 capsule. I observed in most of the evolutions, of 

 which I witnessed a great many, that the filament was 

 not projected with the rapid suddenness observed in 

 many cases, but with comparative slowness, and by 

 degrees; the tip being gradually lengthened, most 

 commonly in a long spiral. In every instance that I 

 could note the fact, the bearded part at the bottom 

 was first projected, and was perfected before the 

 length of the thread proceeded beyond that extent — a 

 convincing proof that the process is one of evolution, 

 and not of simple propulsion. 



THE CLUB-BEARING MEDUSA. 



Thauina7itia8 '} Corijnetes. (Plate XXT.) — Um- 

 brella about Jth inch in height ; bell-shaped ; trans- 

 parent; colourless. (Fig. 1, magnified; 2, nat. size). 



Sub-umbrella, rather more than two-thirds as high 

 as the umbrella, campanulate or sub-conical ; margined 

 with a narrow scolloped veil. Ovaries elliptical, 

 about the outer half of the four radiating vessels, ir- 

 regularly ventricose, reaching to the marginal canal. 

 Their substance, in one that I examined, was com- 



