This Old Spouse, did these catfish have vertically banded tail fins in the store? If not, I'd rule out Corydoras septentrionalis, but I can see where jacko32 is coming from because their snout does look proportionally quite long.
If it was not for the gently sloping snout I'd say C. paleatus.
Whatever species they are, some in that group look very thin and have not been getting enough food since capture and/or could have an internal infection, which depending on how long they have been like that could explain their odd looking shape right now.
Try and get some more photos in a few days or so when they have settled in that we can compare to how they look now, which might make ID easier. Or post at planetcatfish.
Edit: Wondering if these are either a Scleromystax or Aspidoras species, nothing comes close in the Brochis family.