406 



COELENTERATA ANTHOZOA 



CIL 



species of Epizoanthus form colonies on the shells of Gasteropo 

 inhabited by hermit crabs. Parazoanthus tunicans is found o: 

 the stem of a Plumularia ; Parazoanthus separatus, from Jamai 

 is associated with a sponge. The base of the bundle of long 

 spicules of the Sponge Hyalonema (p. 204) is almost invariably 

 sheathed by a colony of Epizoanthus stellaris. 



The only genera occurring within the British area are 

 Epizoanthus (with six species), Parazoanthus (with four species), 

 and Zoanthus sulcatus. 



Of the species of Epizoanthus, E. incrustatus is fairly common, 

 in depths of twenty to eighty fathoms on all our coasts, and is 



frequently commensal with 

 different species of hermi 

 crabs, while E. paguriphil 

 is found in much dee 

 water off the west coast 

 Ireland and is always co 

 mensal with hermit era 

 Parazoanthus anguicomus i 

 found at depths of a hundred 

 fathoms off the Shetlands 

 and west of Ireland, and is 

 a small usually associated with vari 



Fig. 1' 



Zoanthus macgillivrayi, 



colony. The tentacles are shown some- oug ST)ec i es f Sponges 

 what contracted by the preservative. Each 

 zooid is about 25 mm. in length. 

 Haddon. ) 



(After Gerardia savalia is the 

 largest " black coral " of the 

 Mediterranean. The colony begins by encrusting the stem of 

 one of the Gorgoniidae, but soon surpassing its support in 

 growth, it forms a basal horny skeleton of its own and builds 

 up very large branching colonies. A specimen in the British 

 Museum, 1 from twenty fathoms off the island Negropont, is two 

 metres high and two metres wide. The genus appears to be 

 related anatomically to Parazoanthus. 



Fam. 2. Zaphrentidae. This family of Palaeozoic corals is 

 usually placed with the Turbinoliidae or in the separate group 

 Tetracoralla. Eecently Duerden 2 has given reasons, based on 

 the method of increase of the septa in Lophophyllum, for believ 

 ing that their affinities lie rather with the Zoanthidae tha 



1 F. J. Bell, Trans. Zool. Soc. xiii. pt. ii. 1891, p. 87. 

 2 J. E. Duerden, Ann. Mag. Nat. Hist. (7) ix. 1902, p. 381. 



II 



