The identity of Glenodinium has been somewhat confused over the years, due in part to confusion over the identity of its type species, G. cinctum (Loeblich 1980). As a result, many of the references to Glenodinium in the literature refer to unrelated species, while true Glenodinium appears relatively little-studied. One species of Glenodiniopsis, G. steinii, has fared a little better, and its ultrastructure was described in detail by Highfill & Pfiester (1992). Among the more interesting details they noted was that instead of the multiple chloroplasts this species had originally been described as having, it really possesses a single chloroplast but one with multiple lobes, so that if it is viewed in cross-section the lobes might appear as individual plastids.
Fensome, R. A., F. J. R. Taylor, G. Norris, W. A. S. Sarjeant, D. I. Wharton & G. L. Williams. 1983. A classification of living and fossil dinoflagellates. Micropaleontology Special Publication 7.
Highfill, J. F., & L. A. Pfiester. 1992. The ultrastructure of Glenodiniopsis steinii (Dinophyceae). American Journal of Botany 79 (10): 1162-1170.
Loeblich, A. R., III. 1980. Dinoflagellate nomenclature. Taxon 29 (2-3): 321-324.