Very similar to the Navicella, but distinguished from it by not having
an operculum.
Shell irregular, form very variable, depressed or compressed; spire
obliquely inclined to one side; margin entire; cavity large, divided by
a horizontal partition, which gives it the form of a half-decked boat.
Crepidula fornicata.
C. porcellana.
C. aculeata.
C. unguiformis.
C. dilatata.
C. Peruviana.
_C. porcellana._ The brown-spotted Crepidula.
Shell thick, flat, summit not spiral.
_C. aculeata._ The prickly Crepidula.
Oval, brown, roughly striated, vertex recurved, interior blue or purple.
_C. sub-spirata._ The sub-spiral Crepidula. Pl. 32, fig. 2.
Species almost round, summit sub-spiral; colour yellowish white, with a
bluish tinge towards the summit.