L.M.B.C. MEMOIRS. 



No. XV. ANTEDON. 



HERBERT C. CHADWICK, 



Curator of the Port Erin Biological Station, Hon. Lecturer in Marine 

 Biology in the University of Liverpool. 



ANTEDON" BIFIDA, Pennant ( = 6'omr/^W.z rosacea, 

 Linck, of Forhos nnd other autliors), is the most familiar 

 example of the Class C'Rinoidea found in British seas. Of 

 the six species of the p^eniis recognised as British, five 

 appear to be confined to the deeper waters of our seas, but 

 A. bifida has been recorded from depths of a few fathoms 

 only at many points around our coasts. In the L.M.B.C. 

 district it occurs in large numbers off Cemmaes Bay, North 

 Anglesey, at a depth of 10 fathoms, and also oif Bull 

 Bay. It is abundant around the South end of the Isle of 

 Man, and is often found clinging by means of its cirri to 

 the wicker creels used by fishermen for the capture of 

 lobsters and crabs. The fishermen state that specimens 

 are always more numerous on the creels after stormy 

 weather. 



Witli abundant aeration and a moderate amount of 

 light, Antedon may be kept under observation in tanks 

 for months. It is not usually an active animal. By 

 means of its cirri it clings tenaciously to stones, algae, 

 Jiydroids, &c., the arms being widely spread horizontally 

 with the tips more or less flexed towards the disc (PI. I., 

 fig. 1). When disturbed it swims actively and with 

 strikingly graceful movement, the two arms of each pair 

 being invariably flexed and extended alternately (PI. I., 



