Full Idea
Pleasures can be located in a particular part of the body, and can be momentary, and come and go, but this is not the case with happiness.
Gist of Idea
Pleasure can have a location, and be momentary, and come and go - but happiness can't
Source
Richard Taylor (Virtue Ethics: an Introduction [2002], Ch.16)
Book Reference
Taylor,Richard: 'Virtue Ethics: an Introduction' [Prometheus 2002], p.110
A Reaction
Probably no one ever thought that pleasure and happiness were actually identical - merely that pleasure is the only cause and source of happiness. These are good objections to that hypothesis. Pleasure simply isn't 'the good'.