252 THE OCEAN WORLD. 



glance, they seem to proceed now from one side, now from the 

 other. 



The family Callianirida forms a sort of connecting link between 

 the Pleurobrachiada and the Cestidce. Their bodies are smooth and 

 regular, vertically-elongated, compressed on one side and as if 

 lobated on the other ; in substance they are gelatinous, hyaline, and 

 tubular, obtuse at both extremities, with buccal openings between 

 the prolongations of the sides, and two pairs of conical appendages 

 resembling wings, capable of expansion, on the edges of which two 

 rows of vibratory cilia are ranged. A great transversal opening 

 presents itself at one of the extremities, a small one at the other. 

 The animal is furnished with two branching tentacles, but without 

 cilia. 



In the family Cestida we have the genus Cestum. C. veneris, or 

 Venus's Girdle, as it is vulgarly called, has a long, gelatinous, ribbon- 

 like body, fine, regular, and very short, but much extended on each 

 side, while the edges are furnished with a double row of cilia ; the 

 lower surface is also furnished with cilia, but much smaller in size 

 and number. On the middle of the lower edge is the mouth, 

 opening into a large stomach. This alimentary canal runs across the 

 middle of its length, and from it extends, as in the Medusse, a series 

 of gastric canals, which carry the nutriment into all parts of the body. 

 There are many species of Cestum ; among them the best known is 

 C. veneris (Fig. 103), which is found in the Mediterranean, parti- 

 cularly in the sea which bathes the coast of Naples and Nice, where 

 the fishermen call it the sabre de mer sea-sabre. This curious 

 creature unwinds itself on the bosom of the waters, like a scarf of 

 iridescent shades. It is the scarf of Venus traversing the waves, 

 under the fiery rays of the sun, which has coloured it with a thousand 

 reflections of silver and azure blue. 



In the last family, Callymmida, the body is furnished with a pair 

 of antero-posterior oral lobes and other smaller lateral appendages. 

 The tentacles are various, and turned towards the mouth. 



