A Conchological Manual by George Brettingham Sowerby (early reader books .txt) 📖
- Author: George Brettingham Sowerby
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in length; aperture sub-ovate; peritreme sharp, thickened within,
modified by the last whorl; columella with three strong plaits on the
inner edge; outer lip with one fold.--_Obs._ This genus contains but
one or two small recent species, which in some respects resemble
Auricula, from which it is known by the thickness of its shell, and its
globular form. Fig. 299, P. Adansoni. Coast of Africa.
PEDUM. Lam. (_A shepherd's crook._) _Fam._ Pectinides, Lam.
Sub-ostracea, Bl.--_Descr._ Irregular, inequivalve, sub-equilateral,
attached by a byssus passing through a sinus in the lower valve; hinge
toothless, with a triangular area in each valve, separating the
umbones; ligament contained in a groove running across the area;
muscular impressions one in each valve, large, sub-orbicular; both
valves flat, narrow at the dorsal, broad at the ventral extremities;
lower valve with raised edges overwrapping the upper.--_Obs._ This
singular genus, of which only one species is known, differs from
Ostrea, not only in shape and structure, but also in the mode of
attachment, which is by means of a byssus passing through the lower
valve, in Pedum, but by a portion of the outer surface of the shell in
Ostrea. P. Spondyloideum (fig. 179) is the only species at present
known. Moluccas.
PEDUNCLE. See PEDICLE.
PEDUNCULATED. (_Pedunculus_, a little foot.) Attached to external
objects by a hollow fleshy tube, called the Peduncle.
PEDUNCULATED CIRRIPEDES. Lam. An order consisting of molluscs which
have multivalve shells, supported on a peduncle. The genera which it
contains are thus distinguished:
PENTELASMIS. Five valves. Fig. 34.
CINERAS. Five very minute valves distant from each other. Fig.
42.
OTION. The same, but the animal has two auricles. Fig. 43. The
genus Palmina, Gray, has but one.
OCTOLASMIS. Shaped like Pentelasmis, but with 7 or 8 valves.
Fig. 41.
LITHOTRYA. Five valves, peduncle scaly with a plate at the base.
Fig. 39.
SCALPELLUM. Shape square, valves 13, peduncle scaly. Fig. 35.
SMILIUM. Same, but the peduncle hairy. Fig. 36.
IBLA. Four valves, one pair long, one pair short, peduncle
hairy. Fig. 40.
BRISMEUS. Seven valves, even at the base. Fig. 38.
POLLICIPES. Principal valves in pairs, with many smaller valves
at the base. This genus has been divided into _Pollicipes_, and
_Capitellum_, the latter of which is founded upon Pollicipes
Mitellus, Auct. Fig. 37 and 37*.
PELAGUS. Montf. A genus composed of species of AMMONITES, which have
the spire covered by the last whorl, as in Nautilus and have an
umbilicus. ORBULITES. Bl.
PELLUCID. Transparent.
PELORUS. Montf. POLYSTOMELLA, Bl. A genus of microscopic Foraminifera.
PELORONTA. Oken. NERITA _Peloronta_, Auct. Fig. 330.
PENEROPLIS. Montf. A genus of microscopic Foraminifera.
PENICILLUS. Brug. ASPERGILLUM, Auct.
PENTALEPAS. Bl. PENTELASMIS, Auct.
PENTAMERUS. Sow. ([Greek: Pente], _pente_, five; [Greek: meros],
_meros_, part.) _Fam._ Brachiopoda, Lam.--_Descr._ Equilateral,
inequivalve; one valve divided by a central septum into two parts; the
other by two septa, into three parts; umbones incurved,
imperforate.--_Obs._ Dalman remarks upon his genus Gypidia, that it is
most probably identical with PENTAMERUS, Sow. but rejects the name for
two reasons; 1st. That it has already been applied to a class of
insects; 2nd. He disputes the fact of the shell being quinquelocular,
i.e. not counting the triangular foramen in the hinge of the larger
valve as one of the divisions. Fig. 212, 213.
PENTELASMIS. Leach. ([Greek: pente], _pente_, five; [Greek: elasma],
_elasma_, plate.) _Order._ Pedunculated Cirripedes, Lam.--_Descr._
Compressed, conical, composed of five valves; lower lateral pair
sub-trigonal; upper lateral pair elongated, sub-quadrate; dorsal valve
arcuate, peduncle elongated, smooth. Found on floating wood in the
sea.--_Obs._ This genus is known from all others of the order by the
number of valves. Pentelasmis is the genus Anatifera of Lamarck. Lepas
anatifer, Linn. Fossil species of this marine genus are found in the
Calcaire-grossièr of Paris, and in other similar beds. Fig. 34, P.
lævis.
PENULTIMATE WHORL. The last whorl but one.
PERA. Leach. A genus composed of CYCLAS amnica, and other similar
species.
PERDIX. Montf. DOLIUM _Perdix_, Auct.
PERFORATED. (_Perforatus._) Bored through, as the apex of Fissurella,
fig. 245, and Dentalium, fig. 2.
PERFORATION. (_Perforo_, to bore, or pierce.) A round opening, having
the appearance of being bored, as in Haliotis, fig. 338. Sometimes the
term is applied to an umbilicus which penetrates a shell through the
axis to the apex, as Eulima splendidula, fig. 348.
PERIBOLUS. Brug. A genus founded upon young specimens of CYPRÆA, with
their outer lips not formed.
PERIOSTRACUM. A name used by Mr. Gray to signify the substance which
covers the outer surface of many shells, called the _Epidermis_ by most
conchological writers. "Drap Marin" is the name given to this substance
by French Naturalists.
PERIPLOMA. Schum. _Fam._ Myariæ. A genus thus described: "Shell very
thin with the left valve more ventricose than the right; hinge
toothless, ligament double, the external portion thin, the internal
part thick, placed upon prominent, sometimes spoon-shaped hinge laminæ,
and supported by a transverse bone; muscular impressions two, distant,
palleal impression sinuated posteriorly." _Ex._ P. inæquivalvis. fig.
_Genus_, Osteodesma, Deshayes.
PERISTOMATA. Lam. A family belonging to the first section of the order
Trachelipoda, containing the following genera:--
AMPULLARIA. Globose or discoidal; operculum concentric;
including _Pachystoma_, _Lanistes_, _Ceratodes_. Fig. 318 to 320.
PALUDINA. Oval; operculum concentric. Fig. 321.
VALVATA. Globose; operculum spiral. Fig. 322.
PERISTOME. The edge of the aperture, including the inner and outer
lips.
PERITREME. A term used to express the whole circumference of the
aperture of a spiral shell. It is said to be notched or entire, simple,
reflected, round or oval, &c.
PERLAMATER. Schum. (_Mother of Pearl._) MELEAGRINA Margaritifera, Lam.
The pearl oyster.
PERNA. Auct. ("Pernæ concharum generis," Plin.) _Fam._ Malleacea,
Lam.--_Descr._ Sub-equivalve, irregular, compressed, foliaceous; hinge
straight, linear, composed of a series of transverse, parallel grooves,
containing the cartilage and intermediate spaces bearing the ligament;
anterior margin with a sinus for the passage of a byssus; posterior
ventral margin oblique, attenuated. _Obs._ This genus is known from
Crenatula by the straightness, number and regularity of the grooves in
the hinge and the sinus, for the passage of the byssus. Fig. 166, P.
Ephippium. Mostly tropical.
PERSICULA. Schum. A genus formed of MARGINELLA _Persicula_, Auct. and
other species having the spire concealed. Fig. 438.
PERSONA. Montf. (_Mask_). A genus composed of TRITON _Anus_, Auct. and
similar species. Fig. 401.
Class CIRRIPEDES.pg. 3
PETRICOLA. Lam. (_Petrus_, a stone; _cola_, an inhabitant.) _Fam._
Lithophagidæ, Lam.--_Descr._ Equivalve, inequilateral, transversely
ovate or oblong, rather irregular, anterior side rounded; posterior
side more or less attenuated, slightly gaping; hinge with two cardinal
teeth in each valve; muscular impressions two in each valve; palleal
impression entire; ligament external.--_Obs._ The Petricolæ are found
in holes made by the animals in rocks, madrepores, &c. They may be
known from Saxicava by the regularity of their form and the teeth on
the hinge. Fig. 91, 92.
PETRIFIED FINGERS, CANDLES, SPECTRE CANDLES, &c. are vulgar terms by
which fossils of the genus Belemnites were formerly known.
PHAKELLOPLEURA. Guild. A genus composed of those species of CHITON,
Auct. which have bunches of hairs or hyaline bristles on each side of
each valve on the margin. The Chiton fascicularis, found on our own
coasts, is a well known example. Fig. 506.
PHARAMUS. Montf. LENTICULINA, Bl. A genus of microscopic Foraminifera.
PHARETRIUM. König. ([Greek: pharetreôn], _pharetrion_, a
quiver.)--_Descr._ A testaceous body composed of two conical sheaths,
one within the other, perforated at the apex, and joined together near
the oral margin. P. fragile, fig. 3. In describing this genus, which
appears to be the same as ENTALIS of Defrance, Mr. König expresses the
supposition that it may probably belong to the class Pteropoda.
PHASIANELLA. Auct. (_Phasianus_, a pheasant.) _Fam._ Turbinacea, Lam.
Ellipsostomata, Bl.--_Descr._ Smooth, oval, variegated; aperture
entire, oval; outer-lip thin; inner-lip thin, spread over a portion of
the body whorl; columella smooth, rather thickened towards the base;
operculum horny, spiral within; testaceous, incrassated without.
Britain, Mediterranean, &c.; the fine large species are Australian.
Some fossil species are found in the tertiary beds.--_Obs._ The shells
composing this genus are richly marked with lines and waves of various
and delicate colours, and if the genus be restricted to those species
which are smooth, and which have a thick shelly operculum, we may
regard it as well defined; but there are some spirally-grooved species
of TURBO, Linn. which, from their oval shape, have been considered as
belonging to this genus. Such species should not, in our opinion, be
retained in this genus; they belong to Littorina. P. variegata, fig.
367.
PHITIA. Gray. CARYCHIUM, Müller.
PHOLADARIA. Lam. A family of the order Conchifera Dimyaria, Lam. The
animals contained in this family live in cavities bored by themselves
in rocks, wood, &c. They are cylindrical in form. Lamarck here places
PHOLAS and GASTROCHÆNA, the last of which belongs more properly to the
family of Tubicolaria, where we have enumerated it. Pholas has been
divided into _Pholas_, fig. 55, _Martesia_, which has the valves nearly
closed; and Pholadidæa, fig. 56, which has the cup-shaped extension.
The genus Pholadomya, fig. 67, has been added, although of doubtful
character. The genus Galeomma, fig. 58, 59, has also been recently
added.
PHOLADIDÆA. Leach. PHOLAS papyracea, Auct. Remarkable for the
cup-shaped process at the posterior extremity. Fig. 56.
PHOLADOMYA. Sow. (_Pholas_ and _Mya_.) _Fam._ Pholadaria,
Lam.--_Descr._ Thin, rather hyaline, equivalve, inequilateral,
ventricose, posteriorly gaping, elongated, anteriorly short, rounding;
ventral margin rather gaping; hinge with an elongated pit, and lateral
plate in each valve; ligament external, short, muscular impressions two
in each valve, rather indistinct; palleal impression with a large
sinus.--_Obs._ The only recent species of this genus is from the island
of Tortola. Several fossil species occur in rocks of the Oolitic
series. Fig. 57, P. candida.
PHOLAS. Auct. ([Greek: PHôleô], _pholeo_, to lie hid in a cavity.)
_Fam._ Pholadaria, Lam. ADESMACEA, Bl.--_Descr._ Transverse, oblong,
equivalve, inequilateral, imbricated, gaping on both sides, the
anterior hiatus being generally the largest, although sometimes nearly
closed, with the dorsal margin surmounted with one or more laminar
accessary valves; hinge callous, reflected, with a long curved tooth
protruding from beneath the umbones in each valve.--_Obs._ This genus
of marine shells, dwelling in holes formed in rocks, wood, &c. is
easily distinguished from any other nearly allied genus by the curved,
prominent, rib-like teeth. Fig. 55, P. Dactylus; 56. P. papyracea.
PHOLEOBIUS. Leach. Part of the genus SAXICAVA, Auct.
PHONEMUS. Montf. A genus of microscopic Foraminifera.
PHORUS. Montf. TROCHUS agglutinans, Auct. Remarkable for the adhesion
of little pebbles, dead shells, &c. to the outer edge of the whorls,
which are taken up in the course of the growth of the shell. From this
circumstance they are called "Collectors, Carriers, &c." Fig. 360.
Recent species are brought from the East and West Indies; fossil
species are found in the Tertiary beds.
PHOS. Montf. _Fam._ Purpurifera? Lam.--_Descr._ Turrited, thick,
cancellated, varicose; spire pointed, generally longer than the
aperture; aperture rounded or oval; outer lip having internal ridges,
with a sinus near the anterior termination; columella with an oblique
fold; canal short, forming externally a raised varix.--_Obs._ The
raised external surface of the canal, brings this genus near to
Buccinum, while, in general appearance, most of the species more nearly
resemble Murex. They have, however, no true varices on the whorls, but
merely raised bars. Fig. 416, P. senticosus.
PHYLLIDIANA. Lam. A family belonging to the first section of the order
Gasteropoda, Lam. The genera belonging to this family may be
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