ACEPHALA. 259 



mon mass. A transparent jelly-like tube, closed at 

 one end, is studded outside with a great number of 

 little tubercles of a firmer substance, but transparent 

 and polished, each having an orifice at the tip, and 

 a mouth opening into the common tube. In the 

 water they float at the mercy of the waves ; but 

 there is a motion by which the water is sucked into 

 the tube, and entering the mouths is expelled in 

 little streams from the external orifices. One species 

 found in the Mediterranean (P. Gigas) attains a 

 length of fourteen inches. Many of these moving 

 masses of animals exhibit, as they float in the sea, 

 a magnificent effulgence of phosphoric splendour 

 that astonishes, while it enraptures, the midnight 

 voyager. " Nothing can exceed the dazzling light 

 and brilliant colours that these floating bodies ex- 

 hibit, colours varying in a way truly admirable, 

 passing rapidly every instant, from a dazzling red, 

 to saffron, to orange, to green and azure, and 

 thus reflecting every ray into which the prism 

 divides the light, or which is exhibited by the 

 heavenly bow."* 



The remaining Classes of the Mollusca, we must 

 dismiss with a very slight notice, as they possess 

 little to make them popularly interesting. 



Kirby. 



