Not familiar with the term, but will give what input I can, and maybe someone
can expand on it (or, just give us the right answer!).  I am wondering if the
spelling is correct.  There is a term "teleoconch", not used too often, which
refers to the entire gastropod shell EXCEPT the protoconch (teleo means
complete or entire).  Secondly, the prefix "telo" means last (just as "proto"
means first)  - such as in telophase, the last phase of cell division.  So
therefore the term "teloconch" would literally mean the last whorl, or what we
commonly call the body whorl.  However, I don't know that this term is
actually used.  In either case though, I have no idea what a second one would
refer to - a shell generally has only one teleoconch and one body whorl.
 
Paul M.