I don't think Enallagma civile accounts for the very large size. It was distinctly large for a damselfly, and my immediate impression was, it was the largest damsel I'd ever seen. I still think it's Enallagma durum.

Also, the Barlow, Golden & Bangma NJ field guide and Ed Lam's damselfly guidebook both map a costal distribution for durum, and non-costal for civile. Lam specifically refers to durum as a "costal species" in the text. The habitat was tidal salt-marsh.

One more thing, Lam shows the line connecting the eyespots in durum to be thin relative to the size of the eyespot, whereas in civile it's shown to be almost the same width as the eyespot. In this respect, too, durum is a better fit

Please replace this image with the full resolution image for a better look at the terminal appendages, though this may not be necessary. The cerci look very long, supporting the ID of E. civile. E. durum has very short cerci. Despite what you read, Familiar is possible on the coast.


Enallagma civile

I agree with E. civile. I was looking at E. basidens for range, size and markings in error. My mistake, sorry.

It happens. Bluets are not the easiest insects to identify, and there are many species to keep track of. You did have some Enallagma durum also.