Two brothers in London, the Marcuses, got their start in finance based on the success of their father who had built a good business as, of all things, basically a seashell salesman. Living on an ocean port, he collected seashells from arriving seaman aboard ships and made a variety of products from them.
The Marcus brothers eventually got involved in the oil industry, dealing with Russia. When they built their first tankers they named each one after a different kind of seashell, in honor of their father. Later, they struck a deal with oilmen in Texas who make a major discovery there. At this point, they renamed the new company.
They called it -- Shell.