Moved from False Click Beetles.

I asked Eucnemidae specialist Jyrki Muona at the Finnish Museum of Natural History to have a look at these old images to see what he thought. He gamely replied,

It is unfortunate that they are not sharper, however… Those T-rods on mesothorax are really known only for Melasis, Isorhipis (both with pseudosegmented body and this does not seem to be the case) and Nematodes and sort of Dirrhagofarsus. As far as I can see, the larvae were around 1 cm long or even bigger? If so, they really have to be Nematodes, unless you have several new ones around. Great hunting, I must say.

Checking the online coleoptera checklist at the University of New Hampshire, there is only one member of that genus known from New Hampshire, Nematodes penetrans.