In the Devonian of the Cantabrian Mountains at least two
 facies are developed.  The strata of the "south Cantabrian Zone"
 comprise a shallow, high-energy facies characterized by brachio-
 pods and large, solitary and colonial corals.  By contrast, the
 rocks of the region of the "Montó Arruz Zone" belong to a
 deeper, still-water facies and contain "species-poor" cephalopod
 faunas as well as small, solitary corals (superfamily Cyathaxon-
 iaceaa) of which the polycelians are considered characteristic
 of the goniatite-coral assemblages.