Part 67

SCOLYMUS. Sw. A genus of the family "Scolyminæ." Sw. (Turbinella) thus described: "Sub-fusiform, armed with foliated spines; spire shorter; pillar with distinct plaits in the middle." The species enumerated are, "cornigerus, pugillaris, Globulus, Rhinoceros, ceramicus, Capitellum, umbilicaris, mitis." Sw. Malac. p. 304.

SCORTIMUS. Montf. A genus of microscopic Foraminifera.

SCROBICULARIA. Schum. Species of LUTRARIA, Act. of a rounded shape. LIGULA, Leach.

SCROBICULATED. (Scrobiculus, a little ditch or furrow.) Having small ditches or furrows marked on the surface.

SCUTELLA. Brod. (Scutellum, a little shield.) Fam. Phyllidiana, Lam.--Descr. Shaped like Ancylus, pearly within; apex posteriorly inclined, central, involute; muscular impressions two, oblong, ovate, lateral; aperture large, ovate.--Obs. This genus is intermediate between Ancylus and Patella; while in the aspect of the beak, the observer is reminded of Navicella.

SCUTIBRANCHIATA. Bl. (Scutum, a shield; branchiæ, gills.) The third order of Paracephalophora Hermaphrodita, Bl. containing animals with patelliform, but not symmetrical shells, and divided into the families Otidea and Calyptracea.

SCUTUM. Montf. (A shield.) PARMOPHORUS ELONGATUS, Lam.

SECURIFORM. (Securis, an axe; forma, shape.) Hatchet-shaped. Ex. Pedum, fig. 179.

SEDENTARY ANNELIDES. Lam. The third order of the class Annelides, Lam. distinguished from the two other orders by the circumstance of the animal being enveloped by a shelly tube which it never entirely leaves. The order is divided into the families Dorsalia, Maldania, Serpulacea, and Amphitrites. Fig. 1 to 13.

SEA DATE. The common name for PHOLAS Dactylus in the market, given to it on account of its cylindrical shape. Fig. 35.

SEGMENTINA. Flem. NAUTILUS Lacustris, Montagu. Test. Brit. Planorbis nitidus, Drap. tab. 2. Fig. 17 to 19.

SEMICORDATE. Half heart-shaped.

SEMIDISCOIDAL. Forming the half of a circular disc.

SEMILUNAR. Half moon-shaped.

SENECTUS. Humph. A genus of "Senectinæ," thus described by Swainson: "Imperforate; the base produced into a broad flat lobe, spire rather elevated and pointed; the whorls convex; aperture perfectly round; not more oblique than Helix; inner lip entirely wanting, imperialis. Mart. 180. f. 1790. marmoratus. l. M. 448. f. 1." Sw. p. 348.

SEMIPHYLLIDIANA. Lam. The second family of the order Gasteropoda, Lam. the genera of which are distinguished as follows:--

1. UMBRELLA, round, flat; apex central, muscular impression not interrupted. Fig. 233.

2. PLEUROBRANCHUS, apex lateral, sub-spiral. Fig. 232.

SENOCLITA. Schum. CINERAS, Leach.

SEPTARIA. Lam. See TEREDO.

SEPTUM. (Lat.) An enclosure, applied to the thin plate of Crepidula, fig. 239; also to the plates dividing the chambers of multilocular shells.

SERAPHS. Montf. TEREBELLUM convolutum, Lam. Fig. 451.

SERPULA. Auct. (A little serpent.) Fam. Surpulacea, Lam.--Descr. Tubular, narrow, pointed at the apex, gradually widening towards the aperture, attached irregularly, sometimes spirally, twisted, imbricated; keeled or plain; aperture generally round, with the edge simple, or angulated by the termination of external ribs or keels.--Obs. This description is intended to include the genera Serpula, Spirorbis, Vermilia, Galeolaria, &c. The Serpulæ abound in all seas, on rocky shores, at any time covered by water, attached to any kind of marine substance, whether moveable or stationary. The fossil species occur in almost all tertiary strata. Fig. 4 to 7.

SERPULACEA. Lam. The fourth family of the order Sedentary Annelides, Lam. containing the following genera of tubular, irregular shells.

1. SERPULA, attached by a small portion of the shell. Fig. 4.

2. SPIRORBIS, attached by the whole length, coiled. Fig. 5.

3. Galeolaria, with the open extremity raised, and the aperture tongue-shaped. Fig. 6.

4. VERMILIA, attached by the whole length, straight or waved. Fig. 7.