1. Cells with reticulate ornamentation without mucilaginous envelope.

2

1.Cells with reticulate ornamentation and mucilaginous envelope, often within short pines

3

2.Cells with reticulate on surface and surface granules

Trochiscia granulate

2.Cells with reticulate on surface and including long spines and papilla

4

3.Cells with reticulate on surface covered with mucilage and short sharp spines

Trochiscia hamzaoglui

3.Cell with reticulate covered with fine short spines and wide spines like thorn

Trochiscia verrucosa

4.Cells with reticulate ornamentation and long spines including lots of pyrenoid

Trochiscia hystrix

4.Cells with reticulate covered papillae, often within a thin mucilaginous envelope

Trochiscia planctonica