ANIMAL LIFE IN THE MARINE AQUARIUM. Ill 



of different dimensions, figures and shades, and when wit- 

 nessed in combination are inconceivably magnificent. In 

 the tank a singular phenomenon occurs with these Tubu- 

 laria. After a few days' confinement, their heads drop off. 

 Subsequently the stalk darkens again, and new heads are 

 observed internall}'' advancing towards the point whence 

 their precursors had fallen. By and by, these heads drop 

 and are succeeded again by other new ones ; and so on dd 

 infinitum f perhaps, though we are unable to state, from 

 observation, to what extent the curious process is carried 

 out. Our own specimen, from which the artist has made 

 his life-like sketch, has been in the tank since August 

 1857, and blossoms in the novel manner described about 

 once in two days. It looks extremely well beside the 

 Actinia and Serpula. 



CiRRiPEDES. — The Common Barnacle {Pentelasmis ana- 

 tifera) is too well known to need description. The 

 Acorn Barnacles (Balani) usually attach themselves para- 

 sitically, to the shell of a Whelk or some univalve, and 

 spread out a cast-net of the feathery filaments of which 

 their tentacles are composed, to entangle the minute 

 Infusory or Annelid. The Pyrgoma cements himself to 

 the plates of the large Madrejpore^ and travels in this 

 manner an original dead head." 



