. 



398 COELENTERATA ANTHOZOA ch 



Fam. 1. Turbinoliidae. The corals included in this family 

 are mostly solitary forms attached to foreign objects, or living 

 partly embedded in sand. In some cases a small colony is 

 formed by gemmation. 



The genus Flahellum is a solitary coral of a compressed top 

 shape. It has a large number of septa arranged radially on the 

 cup-wall. This cup-wall is not a true theca but an epitheca. 

 In some forms root-like tubes grow out from the sides of the 

 cup near its base and may serve to support the coral on solid 

 objects. In some remarkably fine specimens recently obtained 

 from the Persian Gulf these tubes served to attach the coral to 

 a telegraph cable. Flahellum seems to be cosmopolitan in its 

 distribution. It is usually found in deep or moderately deep 

 water, but some specimens have been dredged in water of 2 to 9 

 fathoms. 



Caryophyllia is a conical coral fixed by a slightly expanded 



base. The cup-wall is a true theca covered below by an epitheca. 



There is a spongy columella surrounded by a single circle of 



^^^ pali. There is one British species, 



t?S#Sjgi^^J C. smithii. It is found attached 



\S3ilSm-lS to sne ^ s ilt a depth of about thirty 



' > A\\ nlf fWn^ fathoms near the Eddystone Lighjtr 



^'^te^i-a^^Hj^BB^^^ 3 house and in other localities in 



sp ^ the English Channel. It also 



Fig. 174. Side view of Trochocyathus occurs between tide marks in the 



hastatus, with exsert septa, well- Scilly Islands, and is found off the 



marked costae (c), and with three * 



spinous projections (Sp) at the base Shetlands, On the West Coast of 



formed by outgrowths froni primary Scotland, and the SOUth-West of 

 costae. (After G. C. Bourne.) ' 



Ireland. The genus is widely dis- 

 tributed and extends from shallow water to depths of 1500 

 fathoms. 'Caryophyllia sometimes occurs in clusters which have 

 the appearance of an incipient colony. This may be due to the 

 embryos fixing themselves upon the epitheca of existing indi- 

 viduals and developing there. It is doubtful whether the species 

 ever reproduce asexually either by gemmation or by fission. 

 When the zooid is fully expanded it projects some distance 

 above the corallum and shows a very transparent body-wall 

 with a crown of some fifty tentacles. Each tentacle terminates 

 in a globose head (Fig. 169) charged with nematocysts. The 

 general colour is pale pink, and there is a broad brown circle 



