Here is a picture from Sanford and Worth 2009 of the Nucella canaliculata with its egg mass:
I'll need help with field work starting in about a year, so if you are interested in looking through some rocky intertidal habitats, keep it in the back of your mind, and I will ask for formal help when the time comes.
Paper reference: Sanford, E., and D. J. Worth. 2009. Genetic differences among populations of a marine snail drive geographic variation in predation. Ecology 90:3108–18.