50 LIFE BY THE SEASHOEE. 



water, show a beauty of form which rivals that of the 

 loveliest of ferns, while others display the coarser fir-like 

 appearance which has given them their common name. 

 The individual zooids are usually much smaller than in the 

 Gymnoblastea, and this fact, together with the greater de- 

 velopment of protective substance, gives them less beauty 

 of colour. One rarely finds among them those lovely rose 

 tints which make the colonies of Clava, Coryne, and 

 Tubularia so delightful to the eye. Though the individual 

 zooids are small, however, the colonies often reach a large 

 size, so that the number of individuals is enormous. The 

 species are difficult to identify, and the beginner must often 

 rest content with the genus, or even with the family. In 

 many cases the determination of the species requires the 

 aid of the microscope. On account of the number of 

 common forms, we shall alter slightly our usual method 

 of procedure, and study chiefly the characters of the 

 families. 



A great number of the littoral forms are Campanularians 

 (fam. Campanularidse), and are distinguished by their bell- 

 shaped cups borne on the end of short stalks. The shape 

 and situation of these cups give the members of the family 

 a certain delicacy of 'form, which makes them readily 

 recognisable. The zooids are remarkable in possessing a 

 large trumpet-shaped proboscis, and generally reach a con- 

 siderable size. Some of the Campanularians give rise to 

 medusoids, others have sessile sporosacs. In both cases the 

 colony produces specially modified cups (gonothecse) ; but 

 while in the one case the cups contain sporosacs within 

 which the eggs ripen, in the other they open early and 

 allow the tiny medusoids to float away, carrying the eggs 

 with them. As each gonotheca may contain many medu- 

 soids, and the colony bears innumerable gonotheca}, it is 

 easy to understand how the countless medusoids found at 

 the surface of the sea in autumn originate. While it is 

 easy to recognise a Campanularian, it is often difficult to 

 determine the species, or indeed in some cases even the 

 genus. In most cases the number of teeth on the margin 

 of the cup, and the number of rings on the stems, constitute 

 important points. 



Of the many Campanularians on the shore, three species 



