Things to note about this composition:

1. It really sounds very tonal, because accidentals are used only in the
last measure.

2. The separation of whole tone scales is not strict.  Even in the first
measure the eighth note G in the right hand is in the same scale as the A
in the left hand.  On the second beat the C in the right hand is balanced
with the B in the left hand, and then the B moves to C (same as the right
hand).  I think of these as "passing tones" or "non-harmonic tones" (terms
used in most theory textbooks).

3. My description of the form is as follows:  A = measures 1 through 4
(composed of two measure sequences).  B = measures 5 through 8
(composed of three one measure sequences with an answer in the final
measure,  
Harpsichord