46 



LIFE BY THE SEASHORE. 



skeleton forms tubes in which the zooids are placed, much 

 as a worm lies in its tube. In examining the more delicate 

 kinds of weeds on the shore, a quick eye will often pick 

 out small yellowish tubes branching among the weed, and 

 bearing small zooids with numerous scattered tentacles, 

 remarkable in having a prominent knob at their tip, 

 whence they are called capi- 

 tate. These zoophytes are 

 species of Coryne and Syn- 

 coryne. Without going into 

 the characters in detail here, 

 let us notice one interesting 

 point in regard to. the repro- 

 duction. In all the zoophytes 

 described as yet we have 

 noticed the occurrence of 

 little sporosacs, structures 

 which lie like little fruits 

 on the wall of the body, 

 and bear the eggs from 

 which new colonies arise. 

 These are present again in 

 Coryne, clustering at the 

 bases of the tentacles, but 



in Syncoryne, although the same little fruits are to be seen, 

 they do not set free eggs, but tiny bells of jelly, which 

 swim away through the water with a gentle pulsating 

 movement. After being set free the bells undergo various 

 changes, and become converted into swimming-bells, or 

 medusoids, called Sarsia (Figs. 6 and 15), often found near 

 the surface of the sea in autumn. They, together with 

 many other medusoids, may be caught by sweeping the 

 surface of the rock pools or the open bay with a fine net 

 on a calm day. Any medusoid resembles more or less 

 exactly a bell in shape, With a stalk or manubrium hanging 

 down in the centre to represent the clapper. We must, 

 however, suppose the upper part of the bell to be much 

 thickened, for it consists of a mass of transparent jelly, 

 which fills up, as it were, the upper part of the hollow of 

 the bell. Further, the mouth of the bell is largely filled 

 up by a transparent shelf which projects inwards from the 



FIG. 14. Syncoryne eximia. 

 After Alhnan. 



