We also practice techniques using similar attacks, except in the first one, instead of cutting from your opponent's lower left rib up to his right shoulder we cut from his left shoulder down to his lower right rib and if you miss you rotate your arm and follow up by cutting his right shoulder down to his lower left rib. It's like carving and "X" over your nage's chest.
The same goes for the sideward slash, if you miss, you rotate your arm and try to cut the other side.
Unfortunately, I'm not sure if there are Japanese terms for these in particular, we usually refer to them as "slashing" either diagonal or sideward. In our case, its more of a real world simulation of a yokomen-uchi and a yoko-uchi.
Hope this helps.
[Edited by adriangan on July 20, 2000 at 06:30pm]