Narceus Species Identification

[The Mantis Menagerie]

I have a bunch of millipedes that I collected over the summer. I thought they were all Narceus americanus, but I just noticed an unusually thick one. I am not sure how I missed its size when I collected it, but I am starting to think it might actually be N. gordanus. It is about 1.5 times the width of the other N. americanus adults. I attached pictures of this individual next to a ruler for identification.

 

[Inverts4life1]

Where were these collected?

 

[The Mantis Menagerie]

They were all collected in NC, which is why I had assumed they were Narceus americanus. This individual seems unusually large though.

 

[Exoskelos]

Probably N. americanus. I have about ten roughly that size I collected from VA a few years back, here's a photo. It might be about to lay eggs or something. On the other hand, it has muted colors like Narceus annularis (my profile pic), looks large enough, but I've not heard of it being as far south as NC, except in maybe isolated pockets.
I live in the range overlap, so i see a lot of both the northern and southern Narceus species. It is surely not N. gordanus though.
N. gordanus has a different kind of head/collum structure than N. americanus or annularis, and its legs are way shorter, and almost always black or dark brown, where N. americanus/annularis has reddish or pinkish legs that are long when compared to N. gordanus.

 

[The Mantis Menagerie]

This is interesting. I guess I just have an unusually large individual.

 

[Exoskelos]

This is interesting. I guess I just have an unusually large individual.

Here's one of my annularis in a communal bin with the regular americanus, its the dark one. The one you have might be annularis, but NC is rather far south to find one.

 

[The Mantis Menagerie]

It does seem a bit thicker, so that might be it.