bit order or byte order for asm370

Hello all,
ON mainframe world,how bit is numberred in a byte and how byte is
numberred in a word?
It seems the bit or byte is number from left to right,and left is the
most significant bit/byte, and when store a word in a memory location,
will high order of the byte be stored in low memory address or high
memory address?

In intel world,bit is numberred from right to left, and low byte of a
word is stored in high memory address, I think in mainframe world, it
is opposite,right?

Regards
Victor