Phonetics and the IPA 5, Exercise 2: description to symbol

close back rounded         [u]
close-mid front unrounded  [e]
open-mid back rounded      [ɔ]
close front rounded        [y]

Primary cardinal vowels among them: [u] (no. 8), [e] (no. 2) and [ɔ] (no. 6).
[y] is not one of the eight primary cardinal vowels (the primary list is
[i e ɛ a ɑ ɔ o u]).

Note: Jones's cardinal [e] is "upper-middle", the chart's close-mid; the
cardinal [ɔ] is "lower-middle", the chart's open-mid.