Lucy could not forbear interrupting her father upon hearing the name of Patella. "How can that genus be mixed with the Conchifera?" she inquired.
"The shell is bivalve," he replied; "raised upon a fleshy peduncle, and fixed to marine substances; the hinge is without teeth, having the form of a duck's beak; the colour a greenish tint. It is found near the Molucca isles.
HIPPONYX MITRATA.
"Yet more remarkable is the Hipponyx mitrata, a common shell, known as Patella mitrata, long supposed to be a univalve, the upper valve only being known. A French naturalist discovered the lower valve, and both have one muscular impression in the form of a horse-shoe.
"I think that it will be best to pause a little before we enter upon the study of the twelfth class, Mollusca, which contains most of the univalves of Linnæus."
MOLLUSCA.
CLEODORA.