33 across (10) ?I?O?I?I?M Metal in the lanthanide series which can be used to make control rods for nuclear reactors due to its ability to capture thermal nuetrons. 44 down (7) T?I?L?S In campanology, a system of change-ringing using seven bells.
Many thanks, scorpiojo and dannyk13. I just couldn`t get google to give up those answers but it didn`t help that I had the wrong pesky animal for 29 down!