356 



COELENTERATA ANTHOZOA 



CHAP. 



large, cylindrical, and spiny. Villogorgia, D. and M. ; widely 

 distributed. Delicate, graceful forms, with thin coenenchym. 

 Echinomuricea, Verrill ; Muricea, Lamouroux ; Paramuricea, 

 Koll ; Acamptogorgia, W. and S. ; Bebryce, Philippi. 



Fam. 5. Plexauridae. In this family we find some of the 

 largest and most substantial Gorgonids. The axis is usually 

 black, but its horny substance may be impregnated with lime, 

 particularly at the base. The coenenchym is thick, and the 

 zooicls are usually completely retractile, and the surface smooth. 



The species of the 



family are princi- 

 pally found in 

 shallow water in 

 tropical 



Fig. 156. Eunicella cavolini. Some branches of a large 

 dried specimen, showing a gall formed by a Cirripede. 



warm or 



The principal 

 genera are : Eu- 

 nicea, Lamouroux. 

 The calices are pro- 

 minent, and not 

 retractile. Plexaura, 

 Lamouroux; Euplex- 

 aura, Verrill. Euni- 

 cella, Verrill. With 

 an outer layer of 

 peculiar torch- 

 shaped spicules. The only British species of this order is 

 Eunicella cavolini (formerly called Gorgonia verrucosa). It is 

 found in depths of 10 to 20 fathoms off the coast of the 

 English Channel and west of Scotland. Occasionally specimens 

 are found in which a gall-like malformation with a circular 

 aperture is seen, containing a Barnacle. Such gall formations, 

 common enough in some species of Madreporaria, are rarely 

 found in Alcyonaria. 



Fam. 6. Gorgoniidae. This family contains some of the 

 commonest and best-known genera of the order. They usually 

 form large flexible branched colonies with delicate horny axes 

 and thin coenenchym. The zooids are usually completely 

 retractile. 



The principal genera are : Gorgonia, Linn. This genus 



