112 CLAVALTTHES. 



guishes it from the Pupse, to some of v>'hicli it bears a very 

 near resemblance. — Hab. Land, in the central and southern 

 parts of Europe, several British species. C. Macascarensis. 

 PL xiv. fig. 295. 



CLAUSIUM. A name applied to the beautiful contrivance whence 

 the genus Clausilia derives its name, consisting of a little bony 

 tortuous plate, placed in a groove in the columella. Here it 

 serves the purpose of a door, which, when not prevented by 

 counteracting pressure, springs forward on its elastic ligament, 

 and encloses the animal in his retirement. The aperture is 

 opened by pushing back the clausium into the groove. 



CLAUSULUS. Montf. Conch. Syst. 1, 179. A genus of micro- 

 scopic Poraminifera. 



CLAVA. Humph. Ceeithium, Lam. 



CLAYAaELLA. Lamarck, 1818. {Clava, a club.) Fam. Tubi- 

 colse. Lam. Pyloridea, Bl. — Descr. Two irregular flattish valves, 

 one fixed or soldered, so as to form part of the side of an irregular 

 shelly tube ; the other free within the tube near the base. — Obs. 

 The shells composing this genus are found in stones, madrepores, 

 &c. and appear to form the connecting link between Aspergillum, 

 which has both valves cemented into the tube ; and Pistulana, in 

 which both are free. Pound recent on the coast of Malta and 

 New South Wales. A fossil species. PL ii. fig. 45. 



CLAVALITHES. Swainson, 1840. A genus composed of some 

 fossil shells, separated from the genus Pusus, which, having the 

 general form of Turbinella Rapa, &c. are considered by Swainson, 

 as holding an intermediate station between Pusus and the 

 Turbinellidse. — Descr. " Unequally sub-fusiform ; the body whorl, 

 and spire, being conic ; and the canal suddenly contracted and 

 attenuated ; terminal whorls papillary ; inner lip thick ; pillar 

 smooth, C. longsevus, clavellatus, 'Nose, ponderosus, Sw."— OS*. 

 The papillary spire may form a sufficient reason for separating 

 this genus from Pusus, while the absence of plates on the 

 columella places them at a still greater distance from Turbinella, 

 PL xxvi. fig. 548. 



