A Conchological Manual by George Brettingham Sowerby (best interesting books to read txt) 📕

   right and dorsal side of the axis, and the umbilicus becomes depressed,

   and often nearly closed. The mouth is lunulate, the edge slightly

   thickened and reflected, and often with a single tooth on the outer

   side of the inner lip.--_Obs._ This genus of land shells is separated

   from Helix on account of the eccentricity of the penultimate whorl. S.

   contusa, fig. 269.

   STRIATED. (_Stria_, a groove.) Marked with fine grooves or lines.

   STRIGOCEPHALUS. Defr. PENTAMERUS, Sow.? GYPIDIA, Dalman.

   STROMBUS. Auct. _Fam._ Alatæ, Lam. Angiostomata, Bl.--_Descr._ Oblong,

   turrited, rather ventricose, solid; aperture generally lengthened,

   terminating posteriorly in a short canal, and anteriorly in an

   emargination or truncated canal; outer lip, when young, thin; when full

   grown, thickened and expanded, lobed at the spiral extremity, sinuated

   anteriorly near the caudal canal.--_Obs._ This well known genus

   includes some species of immense size, commonly called conch shells.

   Most of the recent species are brought from the Indian Ocean. Very few

   fossil species are known. The young shells have very much the

   appearance of cones, the outer lips being thin. There are also several

   species which do not, even when full grown, thicken their outer lips

   very considerably. The genus Strombus is distinguished from

   Rostellaria, by the notch in the outer lip, which in the latter genus

   is close to the canal. Fig. 406, S. pugilis.

   STROPHOMENA. Rafinesque. ORTHIS, Dalman.

   STROPHOSTOMA. Deshayes. A fossil shell, of the family of Colimacea,

   Lam. in some degree resembling Anostoma, having the aperture turned

   upwards towards the spire, it is, however, umbilicated, and is said to

   have an operculum resembling that of Cyclostoma. It is the Ferussina of

   Grateloup. Fig. 534, 5, 6.

   STRUTHIOLARIA. Auct. (_Struthio_, an Ostrich.) _Fam._ Canalifera,

   Lam.--_Descr._ Oblong, turrited, thick; spire turrited, composed of

   several angulated whorls; aperture oval, sub-quadrate, oblique; outer

   lip thickened, reflected, advancing in the centre, receding towards the

   extremities; inner lip thickened, expanded over the columella and part

   of the body whorl.--_Obs._ This singular genus, consisting of three or

   four recent species, is named "Pied D'Autruche" by the French, on

   account of some resemblance in the outer lip to the foot of the

   Ostrich. From New Zealand. Fig. 391, S. straminea.

   STYLIFER. Brod. (_Stylus_, a style; _fero_, to bear.)--_Descr._ Thin,

   pellucid, turbinated; apex a little out of the perpendicular; aperture

   wide anteriorly, gradually narrowing towards the spiral extremity,

   where it terminates acutely.--_Obs._ This is a genus of small,

   transparent shells, found burrowing in the rays of Starfish. There are

   but two or three species at present known, one of which is elongated

   like Terebra, the other nearly globular. Fig. 12, S. astericola. West

   Indies, Gallapagos, and Britain.

   STYLINA. Flem. STYLIFER, Brod.

   SUB. (_under._) Used as a prefix and signifying nearly. Thus a

   bivalve-shell, the valves of which are nearly alike, would be described

   as _sub_-equivalve.

   SUB-APLYSIACEA. Bl. The first family of the order Monopleurobranchiata,

   Bl. containing several genera of Mollusca without shells, and the genus

   Pleurobranchus.

   SUB-BIVALVES. A term of distinction applied by De Blainville, to those

   spiral univalves which have an operculum; these, as they constitute two

   distinct pieces, he considers as forming a medium between univalves and

   bivalves.

   SUB-MYTILACEA. Bl. The sixth family of the order Lamellibranchiata, Bl.

   the shells belonging to which are described as free, rather pearly,

   regular, equivalve; hinge dorsal, laminated; ligament external; two

   muscular impressions; palleal impression not sinuated. This family,

   with the exception of the last genus, agrees with the family Nayades of

   Lamarck, and contains the genera Anodon, Unio, and Cardita.

   SUB-OSTRACEA. Bl. The second family of Lamellibranchiata, Bl. the

   shells of which are described as of a compact texture, sub-symmetrical;

   with the hinge rather complex; one single, sub-central, muscular

   impression, without any traces of palleal impression. This family

   corresponds with the Pectenides of Lamarck, and part of the genus

   Ostrea in the system of Linnæus. It contains the genera Spondylus,

   Plicatula, Hinnites, Pecten, Pedum, Lima.

   SUB-SPIRAL. Not sufficiently spiral to form a complete volution.

   SUBULA. Bl. (_An awl._) A generic name under which M. De Blainville

   includes TEREBRA maculata, Auct. f. 428, together with nearly all the

   species of Terebra, enumerated by Lamarck and other authors; only

   leaving in the latter genus those species, which being more bulbous, or

   ventricose, nearly resemble Buccinum in general form. These last

   mentioned species, such as Terebra buccinoidea, (fig. 247) have been

   formed into a new genus by Mr. Gray, under the name Bullia. If both

   these genera were adopted, the genus Terebra would be extinct.

   SUBULATE. (_Subula_, an awl.) A term applied to shells which are long

   and pointed as in Terebra. Fig. 427, 428.

   SUCCINEA. Drap. (_Succinum_, amber.) _Fam._ Colimacea, Lam. Limacinea,

   Bl. _Sub-genus_, Cochlohydra, Fer.--_Descr._ Ovate, rather elongated;

   aperture large, entire, longitudinal; spire short; outer lip thin,

   continuous with the thin, sharp-edged columella; inner lip spread over

   a part of the body-whorl.--_Obs._ The shells belonging to this genus of

   partly amphibious mollusca, are distinguished from Limnæa by not having

   a fold on the columella The S. amphibia is of a bright amber colour.

   Fig. 265, 266. Temperate and tropical climates.

   SULCATED. (SULCATUS, lat.) Having grooves or furrows.

   SULCI. Grooves or furrows.

   SUTURE. (_Sutura_, lat.) A seam, stitch, joining together. Applied

   particularly to the line which marks the joining of the whorls of the

   spire. The suture is distinguished as _simple_, as in most cases; or

   _double_, when accompanied by a parallel groove close to it;

   _marginated_, when produced into a ledge by the matter which fills up

   and covers it; _obsolete_, when it is filled up so as not to be

   visible, as in the case of Ancillaria.

   SYLVICOLA. Humph. CYCLOSTOMA, Lam.

   SYMMETRICAL, ([Greek: sun], _syn_, similar; [Greek: metron], _metron_,

   proportion.) Both sides alike. Although the term is used thus as one of

   distinction, it is to be observed that no shells are strictly and

   perfectly symmetrical; even in the Nautilus, the apex verges in a

   slight degree towards one side of the shell. Two kinds of univalve are

   symmetrical, or nearly so; 1st. Those which are symmetrically

   convolute, as the Nautilacea and the Ammonacea, which are spiral; 2nd.

   Those which are not spiral, but simply conical, as the patelliform

   shells. Bivalves belonging to the Brachiopoda are also symmetrical.

   _Ex._ Patella, fig. 229. Ammonites, fig. 478.

   SYMPHYNOTA. Lea. A genus of Nayades, in which Mr. Lea proposed to

   include species of the genus UNIO, the valves of which are connate, or

   united at the dorsal margin. We believe that this distinction, as a

   genus, has been abandoned by its author. The fact is, that all the

   Uniones are Symphynotæ when in a young state. In Unio Alatus, (fig.

   147) and Dipsas plicatus, (fig. 142) it will be observed that the

   valves have not separated at the dorsal edge, but are broken lower

   down.

   TAPADA. (Gray. Turton. p. 127.) A division of the genus HELIX,

   containing HELIX aperta, Auct. or the Tapada snail.

   TAPES. Schum. PULLASTRA. Sow.?

   TECTUS. Montf. A genus composed of species of the genus Trochus, having

   elevated, conical spires, and columella notched or truncated by a

   spiral fold. Fig. 359. Trochus maculatus, presents an example.

   TELEBOIS. Montf. A genus of microscopic Foraminifera.

   TELESCOPIUM. Montf. CERITHIUM Telescopium, Auct. fig. 378.

   TELLINA. Linn. _Fam._ Nymphacea, Lam. Conchacea, Bl.--_Descr._

   Sub-equivalve, inequilateral, compressed, rounded anteriorly, slightly

   beaked or angulated posteriorly, the posterior ventral margin having a

   flexuosity; hinge with two cardinal and generally two lateral teeth in

   each valve; muscular impressions, two in each valve, remote; palleal

   impression with a large sinus.--_Obs._ The fold or bending in the

   posterior margin distinguishes this genus from others which it nearly

   resembles. It is composed of some bivalves of great beauty and variety,

   which are found in nearly all climates. Fig. 105, T. radiata, 106, T.

   lingua-felis.

   TELLINIDES. Lam. _Fam._ Nymphacea, Lam.--_Descr._ Sub-equivalve,

   inequilateral, transverse, compressed, rounded anteriorly, slightly

   beaked or angulated posteriorly; hinge with two cardinal teeth in each

   valve, and one lateral tooth in one valve, very near the cardinal

   teeth. Muscular impressions two, distant, palleal impression with a

   large sinus. _Obs._ This genus is distinguished from Tellina in having

   but one lateral tooth near the cardinal teeth. Fig. 107, T. rosea.

   Tropical.

   TENUIPEDES. (_Tenuis_, slender; _pedes_, feet.) The second section of

   the order Conchifera Dimyaria, divided into the families Mactracea,

   Corbulacea, Lithophagidæ, Nymphacea.

   TERACLITA. Schum. CONIA, Auct.

   TEREBELLUM. Lam. (_Terebra_, an augur?) _Fam._ Convolutæ, Lam.

   Angyostomata, Bl.--_Descr._ Smooth, slender, oblong, sub-cylindrical;

   spire obtuse, short, sometimes hidden; (Seraphs, Montf.) aperture long,

   narrow posteriorly, wider anteriorly; outer lip slightly thickened,

   truncated, unconnected at the base with the columella; inner lip thin,

   smooth, nearly straight, spread over a portion of the body-whorl,

   continued in a ridge above the sutures of the spire.--_Obs._ Montfort

   has separated the fossil species with hidden spires, under the name

   Seraphs. (T. convolutum, Lam.) Only one recent species is known, of

   which there are several varieties, one spotted, one marked in

   sub-spiral lines, another in patches. It is brought from the East

   Indies. Fig. 451, T. convolutum; 452, T. subulatum.

   TEREBRA. (_An augur, a piercer._) _Fam._ Purpurifera, Lam.

   Entomostomata, Bl.--_Descr._ Subulate, elongated, pointed, turrited;

   spire long, consisting of numerous whorls; aperture small terminating

   in a short, reflected canal; outer lip thin; columella tortuous;

   operculum horny. The recent species are mostly tropical.--_Obs._ Nearly

   all the species enumerated by Lamarck and other authors are included by

   De Blainville in his genus Subula; those few species which that

   conchologist left in the present genus, being shorter and more

   ventricose than the others, approximate in shape to some of the

   Buccina, and are distinguished by Mr. Gray under the generic name

   Bullia. It seems strange, that De Blainville, being convinced of the

   necessity of separating the two groups, and consequently applying a new

   generic term to one of them, should have given that term to the larger

   number and the more typical species of the Lamarckian genus. Fig. 427,

   Bullia vittata. (Terebra.) Fig. 428, Terebra maculata. (Subula.)

   TEREBRALIA. Sw. A genus of "Cerithinæ," Sw. thus described: "Outer lip

   much dilated, generally uniting at its base to the inner lip; leaving a

   round perforation at the base of the pillar; channel truncate;

   operculum round: palustre. Mart. f. 1472." Sw. p. 315.

   TEREBRATING SHELLS. (_Terebro_, to pierce.) Shells which reside in

   holes pierced in rocks, wood, &c. by means of some corrosive secretion

   of the animal. _Ex._ Pholas, Teredo, &c.

   TEREBRATULA. Brug. (_Terebrans_, bored.) _Fam._ Brachiopoda,

   Lam.--_Order._ Palliobranchiata, Bl.--_Descr._ Inequivalve,

   equilateral, oval or sub-trigonal, ventricose or compressed, attached

   by a tendon passing through an opening in the dorsal, or upper and

   larger valve, the umbo of which advances beyond that of the other

   valve; hinge destitute of a ligament, with two teeth in the dorsal

   valve, locked into corresponding cavities in the ventral, or lower

   valve, and with two curious processes originating at the umbo of the

   lower valve, presenting, in some species, the appearance of fine

   winding tape, advancing towards the front of the valve, and again

   receding to the centre, where the ends unite; muscular impressions two,

   placed near the centre of each valve.--_Obs._ The Terebratulæ are

   included in the genus Anomia in the system of Linnæus. The recent

   species are not very numerous--they are found in all climates. The

   fossil species are more numerous than the recent ones, occurring in the

   secondary and tertiary formations. T. Psittacea, fig. 202.

   TEREDINA. (From Teredo.) _Fam._ Tubicolæ, Lam. Adesmacea, Bl.--_Descr._

   Valves equal, inequilateral, with prominent umbones, as it were

   soldered to the outside of the rounded end of a shelly tube, of which

   they form a part; aperture of the tube partly divided; a flat accessary

   valve placed on the umbones.--_Obs._ This genus, which is only known in

   a fossil state, is distinguished from Teredo, by the valves being fixed

   on the tube, and the tube being closed at one extremity. Fig. 46, 47,

   TEREDO. Auct. (_A piercer._) _Fam._ Tubicolæ, Lam. Adesmacea,

   Bl.--_Descr._ Valves equal, inequilateral; presenting when closed, an

   orbicular figure, with a large angular opening in front, and a rounded

   opening at the back; placed at the anterior extremity