Marsh Bluet,m - Enallagma ebrium

E. ebrium

E. aspersum would have much more black on the body. We will put this one in the guide under Marsh Bluet. Segment 7 is essentially all black and segment 6 half black with long black tip up the center. See Ed Lam, (1) page 74

… john and jane balaban, 3 September, 2004 - 5:25pm

A bluet perhaps

But I'm certain it's not Coenagrion puella. Nearctica doesn't list that species for North America, and indeed a web search seems to indicate that's a European species. Ditto for the other one:

… Troy Bartlett, 12 May, 2004 - 11:26pm

Azure damselfly

V J Hickey: tracked it down: C puella is a European name: UK & West Europe. In Odonata of Mass.,images by Blair Nikula & J Trimble, show M&F as Enallagra aspersum, fam Coenagrionidae...Azure Damselfly. (I had no idea how many Odonata sites there are in the UK.)

… Vincent J Hickey, 13 May, 2004 - 7:59pm