Cryptodromia pileifora, with the commensal sponge beneath which it shelters; seen from the under surface.... The last two pairs of legs, by which the sponge-cap is held in position, are not visible in this view.
Report on the zoological collections made in the Indo-Pacific Ocean during the voyage of H.M.S. 'Alert' 1881-2.London :Printed by order of the Trustees,1884. biodiversitylibrary.org/page/12067736