SCARABUS. Montf. (_Scarabæus_, a kind of beetle.) _Fam._ Colimacea, Lam. Auriculacea, Fer.--_Descr._ Oval, somewhat compressed, smooth, with slightly raised varices; spire equal in length to the aperture, pointed, consisting of numerous whorls; aperture ovate, rounded anteriorly, pointed posteriorly, modified by the last whorl; outer lip sub-reflected, with several prominent folds on the inner edge; inner lip spread over a portion of the body whorls, with several prominent folds.--_Obs._ The shells of this genus are found like Auriculæ, in marshy places. C. imbrium is said to have been found on the tops of mountains, by Captain Freycinet. Fig. 299*, S. imbrium. SCHIZODESMA. Gray. A genus composed of species of MACTRA, Auct. with the ligament placed in an external slit. Fig. 8, M. Spengleri. SCISSURELLA. D'Orbigny. (_Scissus_, cut.) _Fam._ Turbinacea, Lam.--_Descr._ Sub-globose, umbilicated, with a spiral groove terminating at the margin of the outer lip in a slit; spire short; aperture oval, modified by the last whorl; outer lip sharp, with a deep slit near the spire. Recent on the coasts of Britain; fossil in the Calcaire-grossièr.--_Obs._ This genus, consisting of small shells, is known from Pleurotomaria by the shortness of the spire; the latter genus being trochiform. Fig. 340, S. elatior. 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.