FAMILY 6. TURBINACEA. 155 
SCALARIA, Lamarck. 
Testa turriculata, plerumque candidissima, anfractibus segregatim volu- 
tis, costis elevatis, plus minusve numerosis, circumcinctis ; apertura 
rotunda, margine continuo, reflexo, interdum subexpanso, basi ob- 
soleté canaliculata. Operculum corneum, tenue, spirale. 
Amongst the crude conceptions of the early naturalists was a genus 
proposed by Klein under the title of Scala, for the purpose of associating 
all turriculated shells that have the volutions in any way ribbed or ringed. 
The well-known Scalaria pretiosa was to be regarded as the type; Lin- 
neus referred it to his genus Turbo ; but Lamarck, in taking it with its 
cognate species under a more limited character, proposed the present 
genus for their reception, with the new appellation of Scalaria. The 
Scalarize have now become numerous, and their shell is especially distin- 
guished by the elegance and regularity of its growth. The simplicity of 
its formation is indeed remarkable, for the-entire shell is nothing more 
than a gradually enlarging tube, spirally twisting as it increases, and 
becoming periodically encircled with ribs, which exhibit no specific de- 
termination of growth, because each in its turn forms the margin of the 
aperture. 
The shell of Scalaria may be further described as being turriculated, 
and generally very white ; the aperture is round, the margin being con- 
tinuous, reflected, sometimes a little expanded, and obsoletely canalicu- 
lated at the base. The operculum is thin, horny, and spiral. 
Examples. 
PLICCX. Fig.l. 
Scavarta pretiosa, Lamarck, Anim. sans vert., vol. vi. part 2. p. 226. 
Encyclopédie Méthodique, pl. 451. f. 5. a, 6. 
Turbo scalaris, Linnzus. 
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