210393
Other characteristics include a single series of marginals , a fused ring of disc plates , the lack of actinal plates , a spool-like ambulacral column , reduced abactinal plates , and crossed pedicellariae .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 None