ni SEA ANEXOXES. 



303 



THREAD- CELLS OF SEA ANEMONE. 

 A, quiescent ; B, c, D, ruptured. 



species. The well-known genus Anemonia has an adherent base, and is without any pores in 



the sides of the body, which are smooth. Its tentacles, very numerous, are not retractile, but long. 



The margin of the tentaculiferous disc has no coloured bodies, and the tentacles are conical. It 



was called Anthea by Johnston. Anemonia cereus has from 100 to 200 tentacles longer than 



the body, and they are green, or olive and brown tipped with rose, with a brown disc, with green 



radii. It inhabits the rocks of the English Channel. Anemonia 



tuedia, with short tentacles, inhabits the Scottish coasts. Other 



genera have coloured bodies on the outside of the disc. 



The genus Actinia has tentacles that can be retracted, and it 



has the chromatophores, or coloured bodies. Actinia mesembryan- 



themum is the common Red Sea Anemone of the south of England, 



and it is a hardy thing, liking to get out of the water now and 



then on to the rocks, and to remain there closed, and then to 



re-enter by crawling with its disc. It is very voracious, and 



grows to a moderate size, and lives years in confinement. 



Actinia anyuicotna and A. pallida are also English species. 

 The genus is found in all the northern seas, the Medi- 

 terranean, the Atlantic, and on the Pacific coasts. 



Moseley has described Actiniae from 1,075 to 1,350 fathoms' 



depth in the Atlantic, clinging on to the stems of a Mopsea. 



The genus Paractis of the South Seas and Atlantic has no 



chromatophores. 



The pretty Dianthus Anemone belongs to the genus Actinia, and has its disc lobed. An 



allied genus is that of Discosoma, and it contains a huge form, which measures two feet across, 



and which lies flat like a carpet on the mud of the Red Sea. This genus is Mediterranean and 



Pacific in its distribution.* The 

 genus Corynactis has the ten- 

 tacles swollen and sub-spherical 

 at their ends, and Melactis has 

 a protractile mouth and knobbed 

 tentacles. An epidermic enve- 

 lope surrounds the red Capnea 

 sangviinea, and a Dysactis from 

 Guernsey t has a long body, 

 narrow below, with two crowns 

 of tentacles very distinct, but 

 contiguous at their origin. The 

 largest are filiform and white, 

 and the others are small and 

 orange in colour. 



Several genera have wart- 

 like tubercles on the sides of the 

 body, which secrete a sticky 

 substance, and the base, or foot, 

 is very well developed. 



The Crassicorn j Anemone 

 of the south coasts of England 

 belongs to the genus Cereus 

 (Bunodes, Gosse), and is well 



known for its beautiful colours, green, grey, and red, its numerous pointed tentacles, and its voracity. 



Unfortunately it does not live well in aquaria. It has neither chromatophores around the disc 



* The deep sea genus Corallimorphus of Moseley (2,028 fathoms) belongs here. f Dysactis liserialis. 



i Cereus crassicornis. 



ACTINIA MESEMBRYANTHEMU.M. 



