An unglossed root in The Etymologies of the 1930s with derivatives like ᴹQ. helda/N. hell “naked”, ᴹQ. helma “skin, fell” and N. helf “fur” (Ety/SKEL). The root was initially given as ᴹ√SKAL, and various forms had a >> e after ᴹ√SKAL >> ᴹ√SKEL (EtyAC/SKEL).
Middle Primitive Elvish
skal
root. small fish
skal
root. screen, hide (from light), overshadow
skalnā
adjective. veiled, hidden, shadowed, shady
skala
noun. fish
skel
root. *strip
khal
root. (small) fish
khalatirnō̆
noun. fish watcher
skelmā
noun. skin, fell
skelnā
adjective. naked
khol
root. (small) fish
liñwi
noun. fish
A root in The Etymologies of the 1930s glossed “small fish” with derivatives like ᴹQ. hala of the same meaning and ᴹQ. halatir(no)/N. heledir “kingsfisher, (lit.) fish-watcher” (Ety/SKAL²). Elsewhere in The Etymologies Tolkien had ᴹ√KHAL¹ “(small) fish” (Ety/KHAL¹), but there the root was revised to ᴹ√KHOL before the entry was deleted with reference to ᴹ√SKAL (Ety/KHAL¹). TThis primitive khal-form for “fish” also appeared as a note on the title page of The Etymologies (EtyAC/KHAL¹).