Plate XIII. The life history o( Aiirdia. 



{Top left) Scyphistoma hanging from rocks, one ephyra is seen having been just budded off. 



{Top right) A single ephyra. 



{Bottom left) A later stage of young jellyfish. 



{Bottom right) The adult with the four horse-shoe shaped gonads. 



All photographs from hfe by D. P. Wilson 



Atlantic it is common in the Biscay area and from there invades the EngUsh 

 Channel from time to time, in recent years notably in 1954 and 1957. It 

 occasionally becomes carried farther north but records north of the Bristol 

 Chaitnel are extremely rare and it has not been found in the North Sea. Its 

 virulent stinging powers make it a real nuisance to bathers and the 1957 

 strandings in particular caused quite a commotion in the British press. In 

 medical terms it causes 'vasomotor dysfunction and collapse', i.e. the nerves 

 just will not work. Local application of alcohol is effective if applied to the 

 skin quickly as it reduces the toxicity and destroys any ncmatocysts still 



55 



