In encrusting Ctenostomes and in the Membranipora-like Cheilostomes (figs.
The polyps may be solitary, or form colonies, which may be of the spreading or encrusting type, or arborescent, and then always of monopodial growth and budding.
Trophosome encrusting with hydranths of Bougainvillea-type, polyps differentiated into blastostyles, gastrozoids and dactylozoids; gonosome free medusae or gonophores.
As crystals, and as stalactitic, encrusting, reniform, massive, earthy and occasionally pulverulent forms as "sulphur meal."
At low tide the limpet (being a strictly intertidal organism) is exposed to the air, and (according to trustworthy observers) quits its attachment and walks away in search of food (minute encrusting algae), and then once more returns to the identical spot, not an inch in diameter, which belongs, as it were, to it.