Gaṅgā, Himālaya (the snowy mountain) and Śeṣa (king of snakes) all epitomise the colour white. Here the poet Haricandra plays with this idea and, although he doesn’t explicitly make the connection, we can imagine that the flecks of white spray he describes in the first half (of the Sanskrit; the second half in the translation) are like the small white scales that a dried out snake skin sheds.
प्रलम्बनिर्मोकनिभा विभाति या ॥
Gaṅgā seems to be the discarded slough
cast off by the snow-bound mountain
become the king of snakes,
as the wind that races through her woods
rouses her into waves.
9.70 of Dharmaśarmābhyudayaḥ of Haricandra