Thanks for this -
According to the FBA guide*
Nebela tincta should be yellow (maybe there is hint of yellow in the image?)and partially overlain with a smooth layer of organic cement. The Guide also mentions in respect of
Nebela collaris that "Many surveys combine the species with
N. bohemica Taranek. On balance I felt
N. collaris was more probable than
N. tincta. I think the two features in the image below may be pores, but they are lower down the test from the pseudostome than in the Guide's illustrations:
*Guide to the identification of Soil Protozoa - Testate Amoeba, Clarke, K.J., Freshwater Biological Association 2003