254 SEDENTARY ANNELIDES. 



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-grossier. — 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 " Scolyminse." 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. Phyl- 

 lidiana, 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 ; branchice, gills.) 

 The third order of Paracephalophora Hermaphrodita, Bl. contain- 

 ing 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 



