Creeping thing

1:24 And God said, Let the earth bring forth the living creature after his kind, cattle, and creeping thing, and beast of the earth after his kind: and it was so.

 In context, I'd guess that this is the creation of land animals.  But the text here is pretty unclear.  In verse 21, "every living creature that moveth ... after their kind" was brought forth from the sea.  Now we have "the living creature after his kind" from the earth; is that obviously different other than the place of origin?  Then we have the phrase "cattle, and creeping thing"; are those two more things being created, after living creatures, or are those an exhaustive list of the kinds of living creatures that are being created?  Finally we have "beast of the earth after his kind"; that seems distinct. That makes either 4 or 2 kinds of things being created, one of which isn't clearly described as being different from something created earlier.

It is clear that the earth is bringing these forth; that seems to make this verse directly parallel to verse 20.  But verse 20 doesn't have the "and it was so".  Why the subtle change?