Aulacodiscus madagascarensis Tempère ex D.M. Williams, 2021

Williams, David M., 2021, Notes on the diatom collection of the Natural History Museum, London (BM) II- IV. Some type specimens in the genus Aulacodiscus Ehrenberg and nomenclatural notes on Thumia Cleve ex F. B. Taylor, Phytotaxa 480 (2), pp. 152-162 : 157

Aulacodiscus madagascarensis Tempère ex D.M. Williams , nov. sp.

TYPE:— Madagascar ( BM Adams 121 = specimen on Figure 26, holotype designated here) (isotypes: BM Adams 137, BM Adams 502, BM 56700 , BM 62933 ) .

Description:—Cells solitary, radially symmetrical, with conspicuous marginal rimoportulae extending on to valve exterior in hyaline tubes, not reaching centre (annulus), terminating at valve edge in semi-circular slit. Numbers vary, 5–8. Annulus small, central, with rows of loculate puncta situated between marginal rimoportulae. Valves appear dissimilar (compare Figures 22–24, with 25 and 26).