David. The different spelling of many of these names in the Hebrew is due to certain vowels being written out in full (" pl ene"). Where not written they are called "defective". The fact of this difference in Chronicles shows an independent origin.
the seventh. Jesse begat eight sons (1 Samuel 16:5-11 and 1 Chronicles 17:12-14). Here seven are numbered and named, and David is the seventh and the youngest; the eighth may have died young and left no issue. While it was proper to mention the eight in the history, it is unnecessary to do so in the genealogy.