156 CLASS III. GASTEROPODA. ORDER VII. PECTINIBRANCHIATA, 
Pl. CCX. Fig. 2. 
ScALARIA CLATHRUS, Sowerby, Genera of Shells, No. 11. 
Turbo clathrus, Linneus. 
Pl. CCX. Fig. 3. 
Scauaria raricosta, Lamarck, Anim. sans vert., vol, vi. part 2. p. 228. 
Pl. CCX. Fig. 4. 
ScaLaria AustrRaLis, Lamarck, Anim. sans vert., vol. vi. part 2. p. 228. 
Pl. CCX. Fig. 5. (fossil.) 
ScaLaRia FOLIACEA, Sowerby, Genera of Shells, No. 11. 
DELPHINULA, Lamarck. 
Testa turbinata, subdiscoidea, intrd margaritacea, anfractibus szpé laxé 
volutis, ultimo prominente, spinis retusis plerumque ornatis, um- 
bilicum amplum formantibus ; apertura integra, rotunda, margine 
continuo, subreflexo. Operculum corneum, spirale. 
The Delphinule were of the number of those mollusks which were 
separated from the Turbines by Lamarck for the formation of his genus 
Cyclostoma ; but when he discovered the manifest impropriety of asso- 
ciating in one and the same genus a set of animals differing so entirely 
both in their organization and habits, he instituted the desirable separa- 
tion which had been in a manner conceived by Chemnitz, when he 
distinguished them by the common title of Delphinus. The genus Del- 
phinula was introduced for the reception of such of these Cyclostomata as 
he found to be marine; they differ, therefore, in being hydrobranchiate, 
as well as in the composition and external ornament of their shells. 
The shell of Delphinula may be described as being turbinated, some- 
what discoid, and pearly within, the whorls being often loosely rolled, 
with the last rather prominent; they are for the most part ornamented 
with blunt spines, and form a large umbilicus; the aperture is entire 
