The Marginellæ may be divided into two sections; the first bearing in form and habit a strong resemblance to the Cyprææ, and the second gradually losing these indications, and acquiring those of the spiral Volutæ. Among the first are several species, which, like the Cowries, appear destitute of any spire (as in M. cingulata); this part, however, begins to show itself in other successive species very progressively, until it becomes elevated and defined in M. glabella. This shell may be considered the passage to the second division, in which the species lose the simple oval form of the first, and acquire a contracted base and pointed spire, perfectly resembling Voluta undulata Lam. and its allies. The extreme developement of these characters is shown in M. faba.
This genus must, then, be considered as connecting those of Cypræa and Voluta (Lam.); excepting one, the whole of the species are very small; and as the three here selected to illustrate these remarks are frequently seen, and have been often described under other names, little more is necessary than to detail their specific characters.
MARGINELLA cingulata,
Banded Date Shell—upper figures.
M. testâ ovatâ, albidâ, lineis aurantiacis fasciatâ; spirâ obsoletâ, umbilicatâ; columellâ 6 plicatâ.
Shell oval, whitish, banded with orange lines; spire obsolete, umbilicated; pillar 6 plaited.
Voluta cingulata. Dill. 525. 56. Lister. 803. f. 9. Martini, 2. t. 42. f. 419 and 20. Gualt. t. 25. c.? 28. b. Adanson, t. 4. f. 4.
I am happy to record Mr. Dillwyn as the first systematic writer who separated this from Mar. persicula, which has reddish spots, and is quite a distinct species. The present is a pretty, though common shell, and observed by Adanson in great plenty on the African coast.