Marine diatoms of the Bahamas. II. Mastogloia Thw. ex Wm. Sm. Species of the groups Decussatae and Ellipticae

Six species of marine diatoms belonging to Hustedt's groups Decussatae and Ellipticae of the genus Mastogloia werestudied using transmitted light and scanning electron microscopy. Internal and external valve structure is describedfor M. peracuta Jan., M. pseudolacrimata sp. nov., M. rostellata Grun., M. latecostata Hust., M. pseudolatecostatasp. nov., and M. stephensiana sp. nov. The external valve structure of the six species are contrasted to that previouslydiscussed for M. corsicana Grun. in Cl. et Moll. and M. rimosa Cl. Two new species, M. pseudolacrimata and M. pseudolatecostata,were contrasted with two previously described species, M. lacrimata and M. latecostata.