xiii ALCYONARIA ALCYONACEA 349 



but the groups of zooids are short, and do not give rise to 

 branches. 



Fam. 3. Coelogorgiidae. The colony arborescent, attached by 

 stolon-like processes. The stem formed by an axial zooid with 

 thickened body-walls. Branches formed by axial zooids of the 

 second order, and branchlets by axial zooids of the third order, 

 borne either on two sides or in spirals by the main stem. Genus 

 Coelogorgia, Zanzibar. 



Fam. 4. Alcyoniidae. The colonies of this family are usually 

 soft and fleshy, and the spicules, evenly distributed throughout 

 the coenenchym, do not usually fuse or interlock to form a 

 continuous solid skeleton. They may be unbranched or lobed, 

 never dendritic in form. The principal genera are : Alcyonium, 

 Linnaeus, cosmopolitan, but principally distributed in temperate 

 and cold waters. Alcyonium digitatum is the commonest British 

 Alcyonarian. It is found in shallow water, from the pools left at 

 low spring tides to depths of 40 or 50 fathoms, at most places 

 on the British shores. It is stated by Koehler to descend into 

 depths of over 300 fathoms in the Bay of Biscay. There are two 

 principal varieties ; one is white or pale pink in the living con- 

 dition, and the other yellow. In some localities the two varieties 

 may be found in the same pools. Another species, Alcyonium 

 glomeratum, placed in a distinct genus {Rliodophytori) by Gray, 

 and distinguished from the common species by its red colour and 

 long digitate lobes, is found only off the coast of Cornwall. 

 Paralcyonium, Milne Edwards ; Mediterranean. Sclerophytum, 

 Pratt ; sometimes dimorphic, Indian Ocean. Sarcophytum, 

 Lesson ; dimorphic, principally tropical. Lobophytum, Maren- 

 zeller ; dimorphic, tropical. Antliomastus, Verrill ; dimorphic, 

 Atlantic Ocean, deep water. Acrophytum, Hickson; dimorphic, 

 Cape of Good Hope. 



Fam. 5. Nephthyidae. Colonies dendritic. Usually soft and 

 flexible in consistency. Nephthya, Savigny ; Indian and Pacific 

 Oceans. Spongodes, Lesson ; widely distributed in the Indian and 

 Pacific Oceans. 



Fam. 6. Siphonogorgiidae. Colonies often of considerable 

 size. Dendritic. Spicules usually large and abundant, giving a 

 stiff, brittle consistency to the stem and branches. Siphonogorgia, 

 Kolliker ; Bed Sea, Indian, and Pacific tropics. Chironephthya, 

 Wright and Studer ; Indian and Pacific Oceans. Lemnalia, 



