Keyword Album: Ceratosoma%20gracillimum%20Most%20species%20of%20%20Ceratosoma%20are%20best%20identified%20by%20their%20body%20shape%20rather%20than%20their%20colour,%20which%20is%20quite%20variable.%20In%20this%20species,%20Ceratosoma%20gracillimum,%20the%20mantle%20edge%20is%20reduced%20to%20a%20ledge%20around%20the%20head%20end%20of%20the%20body%20and%20a%20lobe%20on%20each%20side%20just%20in%20front%20of%20the%20gills.%20Ceratosoma%20trilobata%20is%20somewhat%20similar,%20but%20in%20that%20species%20the%20anterior%20ledge%20around%20the%20head%20and%20the%20lobes%20are%20connected%20by%20a%20ridge%20down%20each%20side.%20Bill%20Rudman