This genus has its name from the purple liquid produced by the animal,
from which the ancients extracted the Tyrian purple dye. This is the
last genus that presents the appearance of a canal at the base of the
aperture, and therefore rightly precedes the remaining genera of this
family, all of which are without a canal.
Shell oval, thick, generally tuberculated; spire short; the last whorl
much greater than all the others united; aperture oval, greatly dilated,
terminated anteriorly by a canal short, oblique, and notched at the
extremity; the columellar edge almost straight, covered with a callosity
pointed anteriorly; operculum horny, flat, almost semicircular, with
transverse striæ slightly marked; the summit behind.
Purpura Persica.
P. Rudolphi.
P. patula.
P. collumellaris.
P. succincta.
P. consul.
P. armigera.
P. bitubercularis.
P. hippocastanum.
P. undata.
P. hæmastoma.
P. manicella.
P. bufo.
P. callosa.
P. neritoides.
P. planospira.
P. callifera.
P. coronata.
P. sacellum.
P. squamosa.
P. rugosa.
P. textilosa.
P. sertum.
P. Francolinus.
P. limbosa.
P. ligata.
P. cruentata.
P. lapillus.
P. imbricata.
P. lagenaria.
P. cateracta.
P. bicostalis.
P. plicata.
P. fiscella.
P. thiarella.
P. rustica.
P. carinifera.
P. scalariformis.
P. hystrix.
P. deltoidea.
P. unifascialis.
P. retusa.
P. trochlea.
P. semi-imbricata.
P. echinulata.
P. clavus.
P. fasciolaris.
P. vexillum.
P. bizonalis.
P. nucleus.
_P. Persica._ The Persian Purpura. Pl. 28, fig. 4.
Transversely sulcated and striated between the ridges; colour
burnt-umber, ridges yellowish, with dark brown spots; upper ridge and
the superior edges of the volutions mucronate; interior sulcated and
striated.
_P. lapillus._ The common Purpura.
Species small, white, sometimes banded with yellow or brown, with a
scaly surface.