Oval, thin, pearly, with a festooned margin; summit nearly marginal; colour white, shaded with very light brown.
FAMILY III.
Calyptracea. Seven genera.
The genera that constitute this family were separated by Lamarck from the Patella of Linnæus.
1. Parmaphora. The Duck’s-bill Limpet. Three species.
The characteristic distinctions of this shell were first pointed out by De Blainville.
Shell elongated, very depressed; the summit greatly post-medial, and evidently inclined behind; aperture as large as the shell; the lateral edges straight and parallel, the posterior rounded, the anterior sharp and notched in the middle; muscular impression large, elongated oval, slightly open in front.
Parmophora Australis.
P. brevicula.
P. granulata.
P. Australis. The Australian Parmophorus.