With regards to La Pances, I have usually taken it to be a mispelling characteristic enough of the period with homophones, in this case, 'La Pansee' (the thought(s)/the thinking),ie, reflection. For the purposes of historical correctness, however, Pance(s) is used in some mediaeval French texts in reference to the belly (I can only think of the correctness of this coloquial term).
What is interesting, to me at any rate, is that it is used specifically with reference to the Whale's belly in which Jonas spent time... clearly, in my view, as expression of initiation. In fact, one can see initiation chambers as time spent in the belly awaiting re-birth. In that sense, Pope Joan does become significant... but only, I would venture, as symbolic of the initiator into the spiritual world.
