Air Br. in this context undoubtedly means air breathing snails (land
snails and various intertidal and marsh snails fall into this
category, as well as some fresh water snails) - these forms do not
have gills, and instead breath by means of a specialized mantle
cavity which acts (more or less) like a primitive lung.  There is
plenty written on dextral and sinistral ("right-handed" and
"left-handed") snails, but I don't know what your notations "left
whorl" and "right whorl" might mean here, because there is no
correlation between direction of shell spiral and method of
respiration.
 
Paul M.