Grieg: Nineteen Norwegian Folk Tunes, Op. 66

Yester-day, I listened to what excerpts I have of Grieg's Nineteen Norwegian Folk Tunes, Op. 66.  One of the phrases in the sixth piece (Cow-call and Lullaby) sounded familiar, and it didn't take too long to place it.  A similar phrase is in the fourth of Grieg's Symphonic Dances on Norwegian Themes, Op. 64.

I looked up the notation for both pieces, and I was actually surprised by how similar they are:

(click the image to enlarge it)

(notation found here [Op. 64] and here [Op. 66])

In the selections above, that phrase starts in the fourth measure of each (I included only the string parts of the symphonic dance).  They're in the same key and have at least a dozen notes in common.

It pretty clearly illustrates the Norwegian influence on Grieg (as the titles for both pieces also indicate), but I'm having trouble determining which came first.  I should think it's the Symphonic Dances because they have an earlier opus number, but one of my books on Grieg lists the dates for the Symphonic Dances as 1896-1898 (in a letter dated 30 September 1898, Grieg says that the symphonic dances "have just been published") and that of the Nineteen Norwegian Folk Tunes as 1896.  In any case, they were composed at around the same time, so it's interesting to find Grieg using such a similar phrase in both.