Polychaetes: Interstitial families

The minute polychaetes that occur in the interstitial spaces within sandy marine sediments are a diverse phylogenetic assemblage, representing seven separate orders (all of them specifically interstitial) and nine families.

Since they occur together in the same microhabitat, this Synopsis departs from the general style and content of the other Synopses devoted to polychaetes, which are each concerned with one group of related species or families.