(Marcus & Marcus, 1970)
Known only from the Caribbean
4.5mm specimen, dredged from Thalassia in 3m off Channel Cay, Abaco, Bahamas, August 20, 2003. Photo: Colin Redfern.
I think this is what Marcus & Marcus (1970) called Berghia creutzbergi. They described this species from a single specimen from Curacao which they describe as:
Alive 15mm long, brown with white spots on back and cerata. Tentacles had brown bases and white distal halves.... [In preserved specimen ] rhinophores beset with .. tubercles on all sides ..
Colin Redfern's observations confirm that the body is brownish, although with heavy white pigmentation on the dorsum, and that the rhinophores, as described by Marcus & Marcus (1970), are 'beset with tubercles'. As noted by Edmunds & Just (1983), and Redfern, the cerata rock from side to side when the animal is in motion, in a very distinctive movement. It also appears that the brown background colour is caused by zooxanthellae in ducts of the digestive gland, ramifying through the body wall [see reply to Colin Redferns's message.]
I suspect some of the white spotted animals from the Caribbean which have been tentatively identified on the Forum as Spurilla neapolitana [see messages from Colombia - message 1, message 2] may also be Spurilla creutzbergi but I can't see enough detail in their rhinophores. Some, such as David Behrens animal from Belize, cannot be this species because the rhinophores are clearly ridged transversely.
Clearly this is another Caribbean group that could do with some anatomical work.
• Edmunds & Just. 1983. Eolid nudibranchiate Mollusca from Barbados. Journal of Molluscan Studies, 49: 185-203.
• Marcus, Er. & Ev. Marcus. 1970. Opisthobranchs from Curacao and faunistically related regions. Studies on the Fauna of Curacao and other Caribbean Islands, 33: 1-129.
• Redfern. C., 2001. Bahamian Seashells: a Thousand Species from Abaco, Bahamas.
Rudman, W.B., 2003 (October 15) Spurilla creutzbergi (Marcus & Marcus, 1970). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/spurcreu
New records from Brazil 
From: Vinicius Padula, August 23, 2007
Spurilla creutzbergi? from Jamaica
From: Ross W. Gundersen, October 22, 2003
Spurilla creutzbergi from the Bahamas
From: Colin Redfern, October 22, 2003
Aeolid from Florida?
From: Angelo, November 14, 2002