There were two layers of rank determined by the amount of gold lace on the collar and cuff.
One line of gold lace round top of cuff and upper edge of collar:
Ensign: a crown
Lieutenant: a crown and star
Two lines of gold lace round top of cuff and a line along the top and bottom of the collar:
Lieutenants who are Brevet-Majors: a star
Uniforms | Regimental Details