superficiarius

from Bouvier's Law Dictionary, Revised 6th Ed (1856)
SUPERFICIARIUS, civ. law. He who has built upon the soil of another, which 
he has hired for a number of years or forever, yielding a yearly rent. This 
is not very different from the owner of a lot on ground rent in 
Pennsylvania. Dig. 43, 18, 1 and 2. 
    

[email protected]