In this association Tawera spissa and Venericardia purpurata are the dominants, Glycymeris laticostata being entirely absent. The substratum differs from that of the typical formation in having the fine-sand and silt grades a little greater and the coarse grades comparatively small, the bulk of the material being in grades 3, 4 and 5. On account of the lack of the large dead Glycymeris shells there are fewer parasitic animals, and the slight increase in the fine-sand and silt grades accounts for the reduction in species.

The association takes the place of the typical formation in localities where there is no great tidal current. It is found therefore in open exposed bays such as Oneroa, Waiheke Island, and also on the outside and below the Glycymeris+Tawera belt in the case of exposed islets such as the Noises.