SYNOPSIS OF THE DESCRIBED ECHIURA OF THE WORLD
8/22/2006 
                                                         Recent        Fossil      Status
                                                      Gen.  Spec.    Gen.   Spec.
 
PHYLUM Echiura                                         41     175      2       2   
 
CLASS      Echiura                                     41     175      2       2   
 
ORDER            Echiuroinea                           39     170      2       2   
 
ORDER            Sactosomatidea                         1       1      0       0   Complete
 
ORDER            Xenopneusta                            1       4      0       0   Complete