342 NATURAL HISTOET. 



of its prey. These tentacula carry the food to the mouth. 

 The stinging power possessed by them is probably of 

 service in overcoming its prey, like the poison of the 

 Scorpions and other insects. At A you see the under 

 surface, showing the mouth in the middle. The resem- 

 blance in arrangement to the Actiniae is very obvious, 

 the chief difference being that, in the one group, the 

 mouth is above, whUe in the other it is on the under sur- 

 face. The Medusae often reach a considerable size. It 

 is said that they have been seen of three or four feet in 

 diameter, and of even sixty pounds weight. Although 

 they are such watery animals, they eat solid food, for in 

 their stomachs have been found small Crustacea, Mol- 

 lusks, and even Fishes. 



596. The Acalephs generally float near the surface of 

 the water, and sometimes are seen in great abundance 

 basking in the sun, and reflecting its rays in such a man- 

 ner as to make a play of the most brilliant colors. The 

 phosphorescence sometimes seen in the sea is owing 

 chiefly to small Acalephae. Carpenter thus describes the 

 beauty of this phenomenon as witnessed in the warmer 

 latitudes : " The whole surface of the ocean displays a 

 difiiised luminosity, like that of the Milky Way on a clear 

 night. The path of the ship is marked by a brilliant line 

 of glowing light. The waves, as they gently curl over 

 one another (this phenomenon is never seen with a rough 

 sea), break into brilliant spangles. The oars of a boat 

 rowing over them seem dripping with pearls when raised 

 from the water, and every stroke is marked with a new 

 line of brightness. And amid this general splendor, va- 

 ried forms of more glowing lustre are seen 'to move — 

 some like ribbons of flame, some like globes of fire, some 

 gently gliding through the still ocean, others more rap- 

 idly moving just beneath its surface." 



597. To the Ciliograde order of Acalephs belongs the 

 common Beroe, Fig. 269, which is thus described by Dr. 

 Harvey, an English naturalist : " This little creature is 



