Evidence from animals dug up on the shore, from observations on burrowing, or from shell shape indicates that the following species normally lie below the surface with their right valve uppermost: Tellina squalida, T. tenuis, T. fabula, T. donacina, and Arcopagia crassa. Information on the habits of the remaining Tellinidae has not been obtained.

Animals placed on the surface of the soil with the left side up turn themselves over as they burrow. In Arcopagia the shell is turned over beyond the vertical before the animal enters the substratum, but in the remaining species studied the shell is gradually turned over so that it disappears below the surface almost vertically and subsequently completes the turning movement beneath the surface.

The disposition of the siphons of Arcopagia may differ somewhat from that of T. tenuis as described by Yonge, and there is a need for further observation on the siphons of the other species.