Scale bars in all pictures are 100Micrometer. First pic is a cross section of the branche, second is the outer layer of cells, third is the cross section of branchlet and forth is the outer layer of cells of branchlet.
Can You submit a broader view of the specimen (whole thalli/filament). After current pictures, it is similar to Rhodomela sp. beacuase Ceramium has internodes and cortex alternatively.
This seaweed was chewed by rabbit fish and the thalus remained was cylindrical branches! I don't think that this is Rhodomela sp. although the outer cells look a bit similar.