Complex sentence: Morelet was a member of the commission to Algeria, mainly as a natural artist, drawing any natural findings, he took particular interest in mollusks, which he published many works on, particularly the species of Africa.
Split into simpler sentences: Morelet was a member of the Commission to Algeria, primarily as a natural artist, drawing any natural findings. He had a particular interest in mollusks, which he published many works on, particularly the molluscan species of Africa.