HALF AN HOUR WITH SEA-MATS AND SQUIRTS. 153 



every specimen of the larger seaweeds. It is called 

 Botryllus a Greek word signifying a bunch of 

 grapes on account of the animals being connected 

 with each other, much like a bunch of grapes, 

 on a stem. Take a piece of rock or weed thus 

 encrusted with what seem stars set in jelly, and 

 place it in your bell-glass. Immediately you see the 

 beautiful little stars, five to nine-rayed, but whose 

 prevailing number is seven. These are partially 

 imbedded in and held together by the dull slimy 

 skin. Each star is a family, each group of stars a 

 community, and each ray of every star a distinct in- 

 dividual, containing in its innermost recesses all the 

 machinery of life, the respiratory gill-plates and cir- 

 culatory pumps, which a microscopic investigation can 

 discern to be producing minute whirlpools, taking 

 in and throwing out the currents of water needful 

 to the animal's existence. Eound each star, as if 

 marking out the rays more distinctly, is a band of 

 deep purple colour, which gives the stars the appear- 

 ance of being raised in relief. Six species of this 

 beautiful genus are described as occurring in British 

 seas. Fig. 81 will give the reader a good idea of 

 the general appearance of these interesting objects. 

 Perhaps the most beautiful of all the species is 

 Botryllus violaceus, which has six- and seven-rayed 

 stars of a dark blue colour. 



Allied to the above are several other genera, such 

 as Clavelina, Lepralia, and Perophora, some of which 

 may be seen like little gelatinous threads extending 



