3480 



CCELENTERATES 



Most of the numerous species of the scarlet crisp corals (Flabellum) are 

 individuals, and are characterized by the slit-like form of the mouth. At a in the 

 illustration the living animal is seen from above, while b shows a side view of the 



skeleton, which is attached. It resembles a pair of fans 

 fastened along their edges; and just inside the outer 

 edges of the fans is the row of tentacles. The whole 

 animal is as if the upper end of a circular polyp had 

 been squeezed, so that the mouth area, instead of being 

 round formed a long oval (a). An interesting case of 

 budding occurs in these corals, the buds falling off. In 

 the illustration, c shows the bud growing out at the top 

 of an individual like b. In this budding condition the 

 coral might pass for a different species of Flabellum. The 

 bud, however, ultimately falls off (d), but instead of be- 

 MUSHROOM CORAI, BUDDING coming attached, is swept by the waves into some rocky 

 AND FORMING A SMALL fissure, where it spends the rest of its life. Besides the 

 STOCK (natural size). f ac t that it remains unattached, this bud differs from 



its attached parent in a far more important respect. It 



can produce eggs, which the fixed coral cannot do, so that we have here another 

 case of alternation of generations. Out of the egg comes an attached form, which 

 buds and produces the free unattached form, which again produces eggs, and so on. 

 The predominating 

 color of this species is 

 a beautifully intense 

 and yet transparent red, 

 the mouth disc having 

 almost always broad 

 bands of darker red, 

 most marked in the 

 paler specimens. 



The mushroom 

 corals (Fungtidat) are 

 another remarkable 

 group of solitary forms, 

 taking their name from 

 their resemblance to the 

 head of an expanded 

 mushroom turned up- 

 side down. Turning to 

 the figure of Thecocya- 

 thus (on p. 3479), and 

 imagining the circular 



wall pulled down all round, and drawing down the septa so that they radiate out- 

 ward, some idea of a Fungia may be obtained. Their skeletons are remarkable 

 objects, which no one, at first sight, would in any way connect with a sea anemone. 



A DEEP-SEA CORAL, Leptopenus discus (natural size). 



