Noalda sp. 1
Pulau Hoga, Tukang Besi Archipelago, SE Sulawesi, Indonesia, 3 November 1999 at a depth of 38 ft crawling over rubble and filamentous algae. Size: 6 mm. Photo: Lindsay Warren.
This looks very like some drawings of an animal identified by Bob Burn as Noalda exigua Iredale, 1936, a species originally described from Australia from an empty shell. See Burn & Thompson (1998) Order Cephalaspidea In The Southern Synthesis: 943-959 - [Fig 16-31].
I suspect the crescent shaped mark on the posterior shield is an opening to the shell cavity. In Noalda exigua this is a much larger opening. Noalda is considered by Burn & Thompson to be an aglajid but I know of no information on its anatomy.Authorship details
Rudman, W.B., 2002 (July 2) Noalda sp. 1 [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/noalsp1