ABSTRACT

The founder of the genus apparently did not perceive its essential character; Savigny is evident from the excellent figure in the great work on Egypt, perfectly understood / the difference between Chthamalus and Balanus. In the common Chthamalus stellatus, which abounds on the southern British shores, the whole external aspect of the shell is completely masked, owing to its varying shape, its obliterated sutures, its deeply disintegrated and punctured surface, by the corroded condition of its opercular valves. The orifice is sub-rhomboidal, being widest towards the carinal, instead of towards the rostral end, as is usual in Balanus: but in Chthamalus fissus the orifice is narrow and elongated. The colour of the shell is dirty white or dull purplish-red or brown; but in Chthamalus intertextus rich violet-purple. The species are small, not often exceeding half an inch in basal diameter, with the exception of Chthamalus Hembeli, of which have seen a specimen two and three-quarters of an inch in diameter.