XIV ZOANTHARIA ACTINIARIA 377 



Fam. 1. Edwardsiidae. — Several species of this family have 

 been fouiul in the British area. They are very local in their 

 distribution, but sometimes occur in great numbers. 



Edwardsia heaiUem2^sii occurs in shallow water near the 

 shores of the English Channel and has been found in Bantry 

 Bay ; and E. carnca and E. timida have also been found in the 

 Channel. E. tccta is a recently described species from the S. 

 Irish coast, and E. aUmani and E. goodsiri are found in Scottish 

 waters. 



Fam. 2. Protantheidae. — This family, constituted for the 

 reception of three remarkable genera, is now usually included in 

 the order Edwardsiidea on the ground that not more than eight 

 mesenteries are complete. 



The genus Gonactinia exhibits the very exceptional character 

 of having a thick layer of muscles in the body -wall (cf. 

 Cerianthidea, p. 409), and it is also remarkable for the frequency 

 with which it reproduces itself asexually by longitudinal and, 

 more rarely, by tranverse fission. It has been found in Norway, 

 the Mediterranean, and on the reefs of New Caledonia. The other 

 genera of the family are Oractis from California, and Proiantliea 

 from the coast of Sweden. 



Order II. Actiniaria. 



This order contains nearly all the animals popularly known 

 as Sea -anemones. They are usually found in shallow water, 

 attached by a broad basal disc to shells, stones, or sea- weeds. In 

 the Halcampidae, however, the aboral extremity ends in a blunt 

 point as in the Cerianthidea and Edwardsiidea, and the animals 

 live half-buried in sand or mud. The Minyadidae of the southern 

 oceans are pelagic in habit, floating near the surface of tlie sea 

 with tlie mouth turned downwards. They are supported in the 

 water by a bladder, formed by an involution of the pedal disc, 

 and filled with gas. 



Many of the Sea-anemones are found in symbiotic association 

 with other animals. The common Adamsia of the British coasts 

 is found on whelk shells containing hermit crabs. The crab is 

 probably protected from the attacks of some of its enemies by 

 the presence of the Anemone, which in its turn has the advantage 

 of securing some fragments of the food captured and torn to 



