He regarded it as a mollusc, being no doubt deceived by the slug-like appearance given by the antennae.
The Yellow Sandstone contains Archanodon, the oldest known fresh-water mollusc, and plant-remains; the Coomhola Grits are marine, and are sometimes regarded as Carboniferous, sometimes as uppermost Devonian.
Harting informed the present writer that the bird seems to lay its head sideways on the ground, and then, grasping the limpet's shell close to the rock between the mandibles, use them as scissor-blades to cut off the mollusc from its sticking-place.
During the later Tertiary period all these desert regions would appear to have been covered by an Asian Mediterranean or, at all events, by vast fresh-water lakes, a conclusion which seems to be well warranted by the existence of salt-stained depressions of a lacustrine character; by traces of former lacustrine shore-lines, more or less parallel and concentric; by discoveries of vast quantities of fresh-water mollusc shells (e.g.
The mollusc reciprocates by throwing off its embryos on the parent fish, in the skin of which they remain encysted for some time, the period of reproduction of the fish and mussel coinciding.