Described from Japan. Reported here from Hong Kong.
Izu-Osezaki (Suruga Bay, Japan), 28 July, 2001. 2-3M depth. 6-8mm long. Photo: Jun Imamoto.
Grows to about 10mm in length. Charcterised by the bright purple subapical ring on the cerata, and the pair of purple rings on the smooth rhinophores and the oral tentacles.
• Baba, K. (1961) Three new species of the genus Catriona from Japan (Nudibranchia - Eolidacea). Publications of the Seto marine Laboratory, 9(2): 121-128, pl 14, 15.
Rudman, W.B., 2001 (July 30) Cuthona purpureoanulata (Baba, 1961). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/cuthpurp