OH the Genera Orbicula and Cranid of Lamarck. 473
REFERENCES to the accompanying FIGURES.
Tab. XXVI.
Fig. 1. Orbicula l.evis.
a. Attached to a grey flint pebble, which is nearly coated by the
root of an Isis. h. Another view, to show the elevation.
c. Inside of the upper valve, showing the two fringed arms.
d. Inside of the lower valve.
Fig. 2. Orbicula norvegica.
a. A very young specimen.
b. A full grown one.
c. Specimen showing the fringed arms extended like rays beyond
the shell.
d. Inside of the upper valve.
e. Inside of the lower valve. /. Under part of lower valve.
Fig. 3. Crania peksonata.
a. Piece of sandstone, with several specimens of various sizes;
attached to it, from Orkney.
b. Inside of the upper valve, do.
c. Inside of the lower valve, do.
d. Ditto, with the dried animal, do.
e. Inside of a lower valve, from the Mediterranean.
Fig. 4. Crania antiqua. a. Outside of upper valve, b. Inside of do. c. Inside of lower valve.
XXIII. A Com-
