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

apex nearly central, obliquely inclining towards the posterior

   margin; muscular impression partly encircling the central disc, but

   interrupted in front, where the head of the animal reposes, and at the

   side by a siphon, or canal passing from the apex to the margin.--_Obs._

   This siphon, which is in some species very distinct, serves to

   distinguish this genus from Patella. S. Sipho, fig. 231*.

 

   SIPHONOBRANCHIATA. Bl. (_Siphon_, and _Branchiæ_, gills.) The first

   order of Paracephalophora Dioica, Bl. divided into the families

   Siphonostomata, Entomostomata, and Angiostomata.

 

   SIPHONOSTOMA. Guild. A sub-genus of Pupa, consisting of several

   elongated species, which have the aperture detached from the whorls;

   such as P. costata, and fasciata.

 

   SIPHONOSTOMATA. Bl. ([Greek: Siphon], _siphon_; [Greek: stoma],

   _stoma_, mouth.) The first family of Siphonobranchiata, Bl. the shells

   of which are extremely variable in form, but always have a canal or

   notch at the anterior extremity of the aperture. This family partly

   answers to the Canalifera of Lamarck and the genus Murex in the system

   of Linnæus. It contains the genera Pleurotoma, Rostellaria, Fusus,

   Pyrula, Fasciolaria, Turbinella, Columbella, Triton, Murex, Ranella,

   and Struthiolaria.

 

   SIPHUNCLE. (Siphunculus.) A small siphon.

 

   SISTRUM. Montf. RICINULA, Auct. fig. 413.

 

   SKENEA. _Flem._ A genus including some species of EUOMPHALUS and

   CIRRUS.

 

   SMILUM. Leach. _Fam._ Pedunculated Cirripedes.--_Descr._ Thirteen

   pieces, ten of which are in pairs, lateral, subtriangular; one

   posterior dorsal, linear; all smooth; peduncle hairy.--_Obs._ This

   genus is distinguished from Pentelasmis, by the number of its valves,

   and from Scalpellum, by the hairy peduncle. S. Peronii, fig. 36.

 

   SNAIL. The common garden Snail, so destructive to our vegetables,

   belongs to the genus Helix. The water snail, found in ponds, is

   Planorbis.

 

   SOL. Humph. A genus consisting of several species of the genus Trochus,

   and corresponding with the sub-genus Tubicanthus, Sw. Malac. Fig. 349.

 

   SOLARIUM. Auct. (_A terrace, or gallery_.) _Fam._ Turbinacea, Lam.

   Goniostomata, Bl.--_Descr._ Discoidal beneath, conical above, with a

   wide umbilicus, the spiral margin of which is angulated and crenulated;

   aperture trapezoidal; peritreme thin, sharp; columella straight;

   operculum horny, subspiral.--_Obs._ The Solarium Perspectivum, is

   commonly called the Staircase Trochus, from the angulated edges of the

   whorls being seen through the umbilicus, which reaches to the apex, and

   presents the appearance of a winding gallery. The species are not

   numerous, they belong to tropical climates. A few fossil species occur

   in the tertiary formations. Fig. 353, S. Perspectivum.

 

   SOLDANIA. D'Orb. A genus of microscopic Foraminifera.

 

   SOLEN. Auct. (_A kind of shell-fish_, Plin.) _Fam._ Solenacea, Lam.

   Pyloridea, Bl.--_Descr._ Bivalve, transversely elongated,

   sub-cylindrical, equivalve, very inequilateral, gaping at both

   extremities, umbones terminal, close to the anterior extremity; hinge

   linear, with several small cardinal teeth, and a long, external

   ligament; muscular impressions distant, anterior tongue-shaped, placed

   behind the cardinal teeth, posterior irregular, sub-ovate; palleal

   impression long, bilobed posteriorly.--_Obs._ The above description of

   the genus Solen, is framed so as to admit only those species which are

   commonly called Razor Shells, with the umbones terminal, and the

   anterior muscular impression behind them. They are found buried deep in

   the sand, in a perpendicular position, their situation being pointed

   out by a dimple, on the surface. They are abundant in temperate

   climates. Some of the Lamarckian Solenes will be found in the genus

   Solenocurtus, Bl. Fig. 60, 61.

 

   SOLENACEA. Lam. A family of the order Conchifera, Dimyaria Lam. The

   shells belonging to it are described as transversely elongated,

   destitute of accessary pieces, gaping only at the lateral extremities;

   ligament external.--The genera may be thus distinguished.

 

SOLEN. Razor shells, truncated at the extremities. Fig. 60.

 

PANOPÆA. Broad, with prominent tooth. Fig. 65, 66.

 

SOLENOCURTUS. Rounded at the extremities, with internal bar.

       Fig. 61.

 

SOLENIMYA. No teeth, epidermis over-reaching the shell. Fig. 68.

 

GLYCIMERIS. Thick, fulcrum of the ligament prominent. Fig. 67.

 

LEPTON. Flat, scale-shaped. Fig 62.

 

NOVACULINA. Umbones nearly central; covered by a thin epidermis.

       Fig. 63.

 

GLAUCONOME. Oval, margins close. Fig. 64.

 

   SOLENELLA. Sow. (_Solen._) _Fam._ Arcacea, Lam.--_Descr._ Oval,

   equivalve, subequilateral, compressed, covered with a thin, shining,

   olive-green epidermis; hinge with three or four anterior, and numerous

   sharp posterior lateral teeth, arranged in a straight line; muscular

   impressions two, lateral; palleal impression with a large sinus;

   ligament external, prominent, elongated.--_Obs._ This genus partakes of

   the characters of the genus Nucula, and of the family Solenacea. A few

   specimens of the only species known (S. Norrisii, fig. 138.) were

   dredged by Mr. Cuming at Valparaiso.

 

   SOLENIMYA. Lam. (Solen and Mya.) _Fam._ Mactracea, Lau. Pyloridea,

   Bl.--_Descr._ Equivalve, inequilateral, transversely oblong, rounded at

   the extremities with the umbones near the posterior side, covered with

   a shining brown epidermis extending beyond the edges of the shell;

   hinge without teeth; ligament partly internal, placed in the margin of

   an oblique, flattish, posterior rib; muscular impressions two, distant,

   lateral. From the Mediterranean, Australian, and Atlantic

   Oceans.--_Obs._ Solenimya differs from Solenocurtus and the true

   Solens, in having the posterior side of the shell the shortest; in the

   internal ligament; and in being destitute of teeth. It resembles

   Glycimeris, but is not incrassated. Fig. 68, Solenimya radiata.

 

   SOLENOCURTUS. Bl. (_Solen_ and _curtus_, short.) _Fam._ Pyloridea, Bl.

   Solenacea, Lam.--_Descr._ Oval, elongated, equivalve, sub-equilateral,

   with the edges nearly straight and parallel, and the extremities rather

   truncated; umbones not very prominent, sub-central; hinge with or

   without two or three rudimentary cardinal teeth; ligament prominent,

   placed upon thick callosities; muscular impressions two, distant,

   rounded; palleal impression straight, with a deep sinus. East

   Indies--_Obs._ Distinguished from the true Solenes by the central

   position of the umbones and an internal bar reaching partly across the

   shell.

 

   SOLETELLINA. Bl. SANGUINOLARIA radiata. S. Diphos, f. 99. S. livida of

   Sowerby, and similar species, are placed together in this genus.

 

   SPATHA. Lea. A sub-genus of IRIDINÆ, consisting of I. rubens and I.

   nilotica, which have not distinctly crenulated margins. Spatha

   solenoides, of Lea, is the genus Mycetopus D'Orbigny. Fig. 151.

 

   SPHÆNIA. Turt. A genus consisting of a small species resembling

   Saxicava, in general appearance, but having a spoon-shaped process on

   the hinge of one valve. S. Binghamii, Fig. 96.

 

   SPHÆROIDINA. D'Orb. A genus of microscopic Foraminifera.

 

   SPHÆRULACEA. Bl. The first family of Cellulacea consisting of the

   following genera of microscopic Foraminifera: Miliola, Melonia,

   Saracenaria, Textularia.

 

   SPHÆRULACEA. Lam. The fourth family of Cephalopoda, Lam. described as

   multilocular, globular, sphærical, or oval, with the whorls enveloping

   each other; some of them have a particular internal cavity, and are

   composed of a series of elongated, straight and contiguous chambers

   which altogether form a covering for the internal cavity. This family

   contains the genera Miliola, Gyrogona and Melonia.

 

   SPHÆRULITES. Lam. (_Sphæra_, a sphere.) _Fam._ Rudistes, Lam. and

   Bl.--_Descr._ Orbicular, inequivalve, irregularly foliated outside;

   lower valve cup-shaped, depressed; upper valve nearly flat, like an

   operculum.--_Obs._ These fossils are not regarded as shells by all

   conchologists. S. foliacea, Fig. 193.

 

   SPHINCTERULUS. Montf. LENTICULINA, Bl. A genus of microscopic

   Foraminifera.

 

   SPINES. (_Spina_, a thorn.) Thin, pointed spikes.

 

   SPINOSE. (Spinosus.) Having spines or elevated points, as Neritina

   spinosa. Fig. 325.

 

   SPIRAL. (_Spira_, a spire.) Revolving outwards from a central apex or

   nucleus, like the spring of a watch. A shell or an operculum, may be

   spiral, without being produced into a pyramid. Bands of colour, striæ,

   grooves, &c. commencing from the nucleus and following the volutions of

   the shell, are described by the above word.

 

   SPIRAMILLA. Bl. A genus of Serpulacea, differing from other Serpulæ

   principally in the characters of the animal.

 

   SPIRATELLA. Bl. LIMACINEA, Lam. Fig. 224.

 

   SPIRE. (_Spira._) The cone or pyramid produced in a non-symmetrical

   univalve by its oblique revolution downwards from the apex or nucleus.

   The spire, in descriptions, includes all the volutions above the

   aperture. See Introduction.

 

   SPIRIFER. Sow. (_Spira_, a spire; _fero_, to bear.) _Order_,

   Brachiopoda, Lam.--_Descr._ Transverse, equilateral; hinge linear,

   straight, widely extended on both sides of the umbones, which are

   separated by a flat area in the upper and larger valve; this area is

   divided in the centre by a triangular pit for the passage of the

   byssus; interior with two spirally convolute appendages.--_Obs._ This

   genus, which is only known in a fossil state, is distinguished from

   Terebratula externally, by the flat area in one valve, internally, by

   the singular spiral process from which the above name is derived. Fig.

   214, 215. Most of the species belong to the mountain or carboniferous

   limestone.

 

   SPIROGLYPHUS. Daud. A genus consisting of a species of Serpula _Auct._

   which makes a groove for itself in the surface of shells. Serpula

   spirorbis, var. Dillwyn. Fig. 8.

 

   SPIROLINA. Lam. A genus of microscopic Foraminifera.

 

   SPIROLOCULINA. D'Orb. A genus of microscopic Foraminifera.

 

   SPIRORBIS. Lam. A genus composed of species of SERPULA, Auct. which are

   coiled round in a spiral disc like a snake at rest. S. nautiloides,

   fig. 5, is the common little white shell, found upon the shell of

   lobsters.

 

   SPIRULA. (_Spira_, a winding compass.) _Fam._ Lituolata, Lam. Lituacea,

   Bl.--_Descr._ Convolute, smooth, symmetrical, discoid, with parallel

   unconnected whorls, divided into numerous chambers by transverse septa;

   siphon continuous.--_Obs._ This pretty little shell is partly internal,

   only a part of it being visible when on the animal. Fig. 471.

 

   SPISULA. Gray. A genus composed of MACTRA fragilis, and other similar

   species, which have the ligament sub-external, marginal, not separate

   from the cartilage; with the posterior lateral teeth double in one

   valve, and single in the other. M. fragilis, fig. 80, is the species

   figured for Spisula in Mr. Gray's paper on the Mactradæ, in the second

   series of Loudon's Magazine of Natural History. We have since learned,

   however, that it was figured there by mistake, not having been intended

   for a Spisula, but belonging more properly to the genus Mactra, as

   defined by Mr. Gray, whose description of Spisula, is as

   follows:--"Shell ovate, trigonal, sub-angular at each end. Hinge and

   lateral teeth as in Mactra, but hinge of left tooth small. Siphonal

   inflexion ovate." The principal difference between Spisula and Mactra

   is, that the ligament is not separated from the cartilage in the

   former.

 

   SPONDYLUS. Auct. (_A shell-fish_, Ancients.) _Fam._ Pectenides, Lam.

   Sub-ostracea, Bl.--_Descr._ Inequivalve, sub-equilateral, irregularly

   foliaceous and spinose, auriculated, denticulated at the margins,

   attached by the lower and deeper valve; hinge rectilinear, with two

   prominent teeth in each valve, locking into corresponding cavities in

   the opposite valve; umbones separated by a broad, elongated, triangular

   disc in the lower valve; ligament contained in a groove, dividing the

   triangular area in the centre; muscular impressions one in each valve,

   sub-central, sub-orbicular. The Mediterranean, East and West Indies,

   and China, produce Spondyli most abundantly.--_Obs._ This genus is

   remarkable for the richness and beauty of the spines and foliations,

   which adorn the external surface of most of the species, the splendid

   colours by which many of them are varied, and the natural groupings

   formed by their attachment to each other. Fig. 177, and Frontispiece.

 

   SPORULUS. Montf. A genus of microscopic Foraminifera.

 

   SQUAMOSE. (_Squama_, a scale.) Scaly, covered with scales, as the

   pedicle of Pollicipes Mitellus, fig. 37*.

 

   STENOPUS. Guild. ([Greek: Stenos], narrow, [Greek: pous], foot.) A

   genus nearly "allied to the Linnæan Helices, from all of which it

   differs in the curious contraction of the pedal disc, and the caudal

   tentaculum furnished with a gland beneath." The shell is described as

   heliciform, umbilicated, transparent, with the aperture transverse. The

   two species described are Stenopus cruentatus and lividus; they are

   both from the Caribbæan Islands, Guild. Zool. Journ. xii. p. 528, tab.

   15, f. 1 to 5.

 

   STOMATELLA. Lam. See STOMATIA.

 

   STOMATIA. Auct. ([Greek: stoma], _stoma_, mouth.) _Fam._ Macrostomata,

   Lam.--_Descr._ Sub-orbicular, oblong, auriform, variegated without,

   iridescent within; spire depressed; aperture entire, very wide,

   oblique; peritreme uninterrupted. _Obs._ This genus is known from

   Haliotis by being destitute of the series of holes; is distinguished

   from Sigaretus by the substance of the shell, the latter being

   internal, and never pearly. Our description includes STOMATELLA, Lam.

   The Stomatiæ are marine, and belong to the East Indies and New Holland.

   Fig. 335, S. Phymotis.

 

   STORILLUS. Montf. 1, 131. A genus of microscopic Foraminifera, included

   in the genus Rotalites in M. De Blainville's system.

 

   STRAPAROLLUS. Mont. A genus containing some species of HELIX, Auct.

   Generic characters not defined.

 

   STREPTAXIS. Gray. _Fam._ Colimacea, Lam.--_Descr._ Ovate, or oblong;

   when young, sub-hemispherical, deeply umbilicated, with rapidly

   enlarging whorls.