Membranilarnacia donaensis Saxena and Rao, 1984

axonomic senior synonym: Pterospermopsis (as and now Tuberculodinium) vancampoae, according to Jain and Garg (1990, p.108).

Holotype: Saxena and Rao, 1984, pl.1, fig.8
Age: Early Miocene

Original description (Saxena and Rao, 1984):
Membranilarnacia donaensis n.sp. (Pl. I-8-9)
Holotype: Pl 1-8, size 115 µm, slide no. 8374.
Number of specimens studied: 15

Diagnosis: Cyst ncavate, body spherical to subsphaerical in shape. Cyst consisting of thick walled endocyst and thin walled pericyst. Pericoel with a few rods or pillars, rods stout, fibrous, expanded at the distal ends ranging 10-12. Archaeopyle apical, type uncertain, probably type tA. Paracingulum and parasulcus not indicated.

Dimensions: Overall cyst size – 115-122 x 105-110 µm. length of the processes: 10-14 µm. Width of the processes: 8-12 µm.

Comparison: membranilarnacia leptoderma (Cookson & Eisenack, 1958) Eisenack (1963) can be distinguished from the present new species in having the granular body surface. M. polycladiata (Cookson & Eisenack, 1958) Eisenack 1963 is differentiated by possessing thick granular wall and numerous fine processes which divide in such a way as to give a funnel-like appearance. M. reticulate Williams & Downie in Davey et al., (1966) differs in possessing a reticulate membrane enveloping the central body.
Occurrence: Dona Member, Bhuban Formation, Surma Group.
Type locality: 160.5 km-stone, Sonapur-Badarpur Road Section, Meghalaya.
Type horizon: Dona Member, Bhuban Frmation, Surma Group, Lower Miocene.