QUOTE(owainsutton @ Jul 16 2012, 03:06 PM)
It's hard to say without seeing the context - it could just as easily be intended to indicate either a subtle bow change or a clear articulation.
If this is any help, it's a sonata by B. Romberg (so I think late classical). The first of the two trills has an appoggiatura indicated, the second has the ending indicated (I have been doing too much music in French and I can't remember what the proper English term is but what I mean is (B)-A-B-A-B-A-B-A etc. (G-A) the trill being on the A and the notes in brackets the appoggiatura and the ending if that makes any sense).