Pl. 12.
1 Pteroceras, 2 Strombas, 3 Cassidaria, 4 Cassis, 5 Ricinula, 6 Purpura, 7. Monoceros, 8 Concholepas, 9 Harpa 10 Dolium, 11 Buccinum 12 Eburna, 13 Terebra, 14 Columbella, 15 Mitra, 16 Voluta 17 Marginella 18 Volvaria, 19 Ovula, 20 Cyprea, 21 Terebellum, 22 Ancillaria, 23 Olivia, 24 Conus, 25 Spirula, 26 Nautilus 27 Argonauta, 28 Carinaria.
P. S. Duval, Lith. Phila.
CONCHOLOGY.
CLASS I.
ANNULATA.
Animal soft, elongated, vermiform, naked or inhabiting a tube, which it never entirely quits; the body furnished either with segments or transverse wrinkles; often without a head, eyes or antennæ; without articulated feet, but most of them having in their place bristly, retractile knobs, disposed in lateral rows: mouth subterminal, either simple, orbicular, with lips, or in the form of a proboscis; often with jaws, a knotted longitudinal medulla, and nerves for sensation and motion; the blood red, circulating by means of arteries and veins: respiration by external or internal branchiæ, which are sometimes imperceptible. Four Families.
FAMILY I.
Dorsalia. Two Genera.
1. Genus Arenicola.
Animal. The gills, or respiratory organs dorsal, or disposed lengthways on the body.
Shell. Supposed to be tubular. One species.
Arenicola piscatorium.