The shells constituting this genus are found in all seas; they are well
known, and many of them are very beautiful.
The form is usually regular; their surface is adorned with elevated
divergent ribs, varying in number from five to thirty, proceeding from
the beaks and terminating at the margins in a scalloped outline.
Some are equivalve, others have one valve flat and the other convex; the
colours of the upper valve are brighter than those of the lower.
There is considerable variation in the size and form of the ears, which
in some species are equal or nearly so, but in others are unequal; some
are so small as to be nearly indistinct. The ribs are variously
diversified with beautiful colours and delicate checker-work; the
margins are mostly crenated, and oftentimes beautifully coloured.
These shells were formerly worn by Pilgrims on their hat or coat, as a
mark of having been to the holy shrine in Palestine.
Shell free, regular, thin, solid, auricled, equivalve, equilateral;
summits contiguous; hinge without teeth; a ligamental membrane through
all the length of the hinge, besides a short, thick ligament, almost
entirely internal, which fills a triangular cavity under the summits;
one sub-central muscular impression.
Pecten maximus.
P. medius.
P. Jacobæus.
P. bifrons.
P. ziczac.
P. Latirentii.
P. rastellum.
P. turgidus.
P. flagellatus.
P. aspersus.
P. flavidulus.
P. plica.
P. pleuronectes.
P. obliteratus.
P. Japonicus.
P. Magellanicus.
P. purpuratus.
P. lineolaris.
P. radula.
P. nodosus.
P. pallium.
P. pes-felis.
P. tigris.
P. imbricatus.
P. histrionicus.
P. sauciatus.
P. opercularis.
P. asperrimus.
P. senatorius.
P. aurantius.
P. florens.
P. varius.
P. sanguineus.
P. sinuosus.
P. ornatus.
P. glaber.
P. sulcatus.
P. virgo.
P. unicolor.
P. griseus.
P. distans.
P. Isabella.
P. lineatus.
P. flabellatus.
P. irradians.
P. flexuosa.
P. dispar.
P. quadriradiatus.
P. Islandicus.
P. inflexus.
P. pellucidus.
P. Tranquebaricus.
P. gibbus.
P. miniaceus.
P. pusio.
P. hybridus.
P. sulphureus.
P. lividus.
_P. glaber._ The glabrous Scallop. Pl. 15, fig. 4.
Species of which the two valves are ribbed and almost equally convex,
the right a little less, and having its inferior ear less broad than the
left, so as to produce a kind of groove for the passage of the byssus.
_P. Jacobæus._ The scallop of St. James.
Species very inequivalve; the left valve being very flat, the right
convex; ears equal.
_P. pleuronectes._ The sole Scallop.
Species equivalve, not closing; surface smooth and ribbed within; one
valve perfectly white, the other of a brownish or reddish colour.