US dragonfly (1 Viewer)

[Surreybirder]

A friend in the US sent me this photo. I've been trying to ID it but it doesn't quite match any of the photos in the only book I have on N. American odos.
The photo was taken near Boston, Mass. My friend doesn't know much about dragonflies but I thought I'd like to tell her what it is. I thought it might be an eastern pondhawk but the pterostigma look wrong. I also wondered about great blue skimmer, but the photos in my book show much more marking on the wing.
Any help appreciated!

 

[Jim M.]

Male Slaty Skimmer (Libellula incesta)

 

[Surreybirder]

Thanks, Jim, I obviously didn't look hard enough! Although, to be fair to myself, the picture in 'Dragonflies through binoculars' is tiny!