Plate P6. Scale bar = 10 µm. Sample 183-1138A-52R-3, 4 cm. 1A-1C. Biantholithus sparsus; (1A) crossed polarizers, (1B) transmitted light, (1C) differential interference contrast light (DIC). 2A, 2B. Markalius inversus; (2A) crossed polarizers, (2B) DIC. 3A, 3B. Placozygus sigmoides; (3A) crossed polarizers, (3B) DIC. 4A, 4B.Cruciplacolithus tenuis; (4A) crossed polarizers, (4B) DIC.

Plate P6. Scale bar = 10 µm. Sample 183-1138A-52R-3, 4 cm. 1A-1C. Biantholithus sparsus; (1A) crossed polarizers, (1B) transmitted light, (1C) differential interference contrast light (DIC). 2A, 2B. Markalius inversus; (2A) crossed polarizers, (2B) DIC. 3A, 3B. Placozygus sigmoides; (3A) crossed polarizers, (3B) DIC. 4A, 4B. Cruciplacolithus tenuis; (4A) crossed polarizers, (4B) DIC.