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Psammothidium chlidanos differs from P. helveticum by lacking terminal raphe fissures curved to opposite sides. It differs from P. daonense and P. helveticum by its transversely rectangular central area on the rapheless valve. P. subatomoides has shorter elliptical valves. P. bioretii has wider elliptical valves with lower striae density and the raphe is at an oblique angle to the apical axis.

LM scalebar = 10 µm
Psammothidium chlidanos LM3 Psammothidium chlidanos LM1 Gsn23387  Pschlidanos 2A Ed Gsn23387  Pschlidanos 2B Ed Gc44453  Acchlidanos Type3 Ed 1 Gc44453  Acchlidanos Type6 Ed Gs100739  Pschlidanos 1A Ed
Length Range
12-18 µm
Width Range
4.8-6.2 µm
Striae in 10 µm
27-33

Psammothidium bioretii

(Germain) Bukht. and Round 1996

Psammothidium bioretii LM3 Psammothidium bioretii LM2 Psammothidium bioretii LM1 Mo000019 1A Ed 3 Mo000019 1B Ed Gs028733  Psbio 1A Ed Gs028733  Psbio 1B
Length Range
12-26 µm
Width Range
5.3-9.1 µm
Striae in 10 µm
23-27

Psammothidium subatomoides

(Hust.) Bukht. and Round 1996

Psammothidium subatomoides LM10 Psammothidium subatomoides LM2 Psammothidium subatomoides LM4 Psammothidium subatomoides LM6 Psammothidium subatomoides LM8
Length Range
5.5–11 µm
Width Range
3.2-6.0 µm
Striae in 10 µm
30-40

Psammothidium helveticum

(Hust.) Bukht. and Round 2007

Gs100739  Pshelv 2A Ed Gs100739  Pshelv 2B Ed Gsl00810 13A Ed Gsl00810 6A Ed Gsn23403 1A Gsn23403 1B Gs100739  Pshelv 3B Ed
Length Range
12-26 µm
Width Range
5.1-7.8 µm
Striae in 10 µm
24-30

Psammothidium daonense

(Lange-Bert.) Lange-Bert. 1999

Psammothidium daonense LM3 Psammothidium daonense LM2 Psammothidium daonense LM1 Gs100739  Psdao 4A Ed Gs100739  Psdao 4B Ed Mo000019 1A Ed Gs007601  Psdao 1A Ed
Length Range
9-23 µm
Width Range
4.8-7.5 µm
Striae in 10 µm
24-30