This critter was a bit hard to identify, but master brancher Dr. Terry Gosliner came to our rescue. I should have known that that reddish brown marginal band with a submarginal white band were the hallmark of this species. The orange-brown coloration on the dorsum varies greatly as seen in Mike's photos, here. Note how different his photos are from the photo in NSSI 2nd Edition. All have the characteristic marginal bands that give this species its name. This is demonstrated again on Bill Rudman's Sea Slug Site.

This species is widespread throughout the tropical Indo-West Pacific.

References:

Rudman, W.B. (1984) The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: a review of the genera. Zoological Journal of the Linnean Society, 81: 115-273.
Rudman, W.B. (1985) The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: Chromodoris aureomarginata, C. verrieri and C. fidelis color groups. Zoological Journal of the Linnean Society, 83: 241-299.
Rudman, W.B. (1986) The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: The genus Glossodoris Ehrenberg (=Casella, H. & A. Adams). Zoological Journal of the Linnean Society, 86(2): 101-184.