"Starbucks had to change their corporate logo because some consumers found the suggestive split tail of their topless siren too lurid and sexually suggestive. A simplified logo was introduced, hiding the siren's breasts under waves of hair, and that in turn was cropped and enlarged so the split in the siren's tail would no longer show. The only indication now that the female icon is a sea creature is in the wavy lines, which originally were part of the representation of the two tails. And yes, although the image is that of a split-tailed sea creature, it is a siren. More specifically, it is a double-tailed siren, a baubo siren, which The Woman's Dictionary of Symbols and Sacred Objects points out, is "a cross between a mermaid and a sheila-na-gig" and is found as a decorative motif in many European churches and cathedrals. "Her suggestive pose, like that of the sheila-na-gig, referred to female sexual mysteries in particular."
-Heinz Insu Fenkl