Dear Robert,
 
Points well taken.  However, if you examine the wording of the ICZN
statement supplied by Jose, you will note that the binom is not
referred to as the "species name" but rather as the "scientific
name".  The document further states that the "scientific name" is
composed of the genus name plus the "specific" name.  In zoological
terminology, the meaning of "specific" is not simply "definite" as in
general conversation, but rather "characterizing or distinguishing a
species".  Therefore my opinion remains unaltered, pending anything
and everything which may follow hereafter.  The "scientific name"
which we use to designate a species is composed off the genus name (a
noun) followed by the specific (or species) name (as you indicated, an
adjective).
 
Regards,
Paul