ZOOPHYTA. 17 



Actiniadce chiefly affect the rocks between tide- 

 marks, but are not fixed, and the elegant Lucer- 

 narice hang from slender sea-weeds. Our few 

 native Madrepores (Caryophyllacea) are either 

 natives of deep water, or are permanently fixed to 

 rocks at the lowest tide-level, on the Devon and 

 Cornwall coasts. The Alcyonaria are confined to 

 deep water, except that small specimens of Alcy- 

 onium are occasionally found on rocks and under 

 ledges within tide-marks. 



Identification. — The points to be noticed are 

 mainly these : — the cavity of the body, whether 

 simple, or divided by radiating membranous plates ; 

 the increase, whether by buds from the sides, or 

 by embryos discharged ; if the latter, whether 

 from the mouth, or from proper capsules; the 

 presence or absence of a tube ; the arrangement of 

 the cells or buds in the compound tribes; the 

 nature, texture, and arrangement of the solid 

 skeleton; the number, form, and arrangement of 

 the tentacles ; the emission of poisoning threads ; 

 the adhesion or freedom of the base; and the 

 general figure of the animal. 



Authorities. — Dr. Johnston's "History of British 

 Zoophytes," Mr. Dana's magnificent treatise "Zoo- 

 phytes," in the American Exploring Expedition, 

 and personal observation. 



ZOOPHYTA. 



Animals of radiate structure, of gelatinous or 

 fleshy substance, with a crown of tentacles sur- 

 rounding the entrance to the stomach : furnished 

 with offensive weapons in the form of capsules 

 imbedded in the tissues, each of which incloses a 



C 



