Note
Male specimens of Coelopleurus floridanus have tubular genital papillae which are conspicuous during spawning. Papillae are also visible in live, alcohol-preserved, and dried specimens. Females have small, inconspicuous, conical papillae. No other external differences between males and females of this species were found, and no secondary sex characters of this nature were found in any other genera in the Order Arbacioida. This is apparently the first record of dimorphic genital papillae in a deep-sea regular echinoid. A survey for dimorphic papillae in some other deep-sea regular echinoids was negative.