The Circular Chinese Hat, Calyptraea centralis (Conrad, 1841) is the least common among the local species of the Slipper Snail family Calyptraeidae. Its circular shell reaches about 0.5 in diameter; the apex on "top" of the shell is centrally located, and the shell "aperture" is represented by a sinuous (sigmoid), flaring shelf "under" the shell. The shell color is white or off-white, sometimes slightly translucent. As other members of the family, Circular Chinese Hats are filter-feeding marine gastropods (marine snails).
![The Circular Chinese Hat, Calyptraea centralis, from Sanibel Island. Photo by José H. Leal.](https://static.wixstatic.com/media/7f077a_c28d447f77f84ae99311948ae8b85966~mv2_d_2940_2658_s_4_2.jpg/v1/fill/w_147,h_133,al_c,q_80,usm_0.66_1.00_0.01,blur_2,enc_auto/7f077a_c28d447f77f84ae99311948ae8b85966~mv2_d_2940_2658_s_4_2.jpg)
The Circular Chinese Hat, Calyptraea centralis, from Sanibel Island. Photo by José H. Leal.