| Abstract: | Using scanning electron and light, microscopy, several hundred specimens of Campylostylus normanianus (Grev.) Gerloff, Licmophora abbreviata Agardh, L. gracilis var. anglica (Kütz) Per. et Per., and L. flabellata (Carm.) Agardh were examined to elucidate their valve morphology. These species were found to be heterovalvar with respect to the presence of the labiate process in the basal apices of the cell, although one was always present at the head pole of each valve. This form of heterovalvar may be one basis for partitioning the large and variable family Diatomaceae. Because of the similar valve morphologies exhibited by C. normanianus and Licmophora species examined, it is recommended that Campylostylus normanianus be placed in the older genus Licmophora, as L. normaniana (Grev.) Wahrer. |
