Opalescent swirls. Fenton made some perfume bottles for Wrisley in hobnail, but I have no information on the glass manufacturer of this pattern.
A viewer wrote me that she has a similar bottle. One sticker on the bottom reads "Clifton Distributors Toronto." The other sticker is "Wistaria Wrisley New York Chicago Cont 4 1/2 oz."
Her bottle is "more opaque white glass, but the same shape and cap."