This species differs from N. brasiliensis in that the central area is wider, slightly panduri-form, while the puncta are regular near the central area; intergrades occur between the two species (Pl. 4, Fig. 54b), and it seems doubtful whether they can be maintained. Length. 80–90μ. Distribution. Australia: Port Hacking, Lake Macquarie, Gippsland Lakes. New Zealand: Auckland Harbour. Recorded from Australia by Østrup (1910). 197. Navicula radiosa Kütz. (Pl. 5. Fig. 55.) Kütz., 1844, 91. Boyer. 1927b, 3, 97. Cleve-Euler, 1953b, 816. Cells solitary; valves lanceolate, narrow, with sub-acute ends; axial area very narrow, indistinct; central area small; costae radiate in the middle, convergent at ends. Length, 80–120μ. Distribution. Fresh to brackish water Australia: Lake Dobson, Port Hacking. Recorded from Australia by Østrup (1910). 198. Navicula meniscula Schumann (Pl. 5, Fig. 56.) Schumann, 1864–9. Hust in A.S., 1934, 399, 30–33. Hohn, 1951, 16, 34, 129. Cells solitary, valves elliptic-lanceolate with acute ends; costate, punctate, somewhat irregular near central nodule. Length, 50μ. Distribution. Fresh water. Australia: Lake Dobson, Tasmania. 199. Navicula spectabilis Greg. (Pl. 5, Fig. 57.) Greg, 1857, 481. Boyer 1927, 412. Cleve-Euler 1953b, 107, 712. Valves elliptic; lateral areas broad, constricted in middle, and tapering sharply at apices, with faint striae in middle of area; a row of punctate striae on each side of axial area; differs from N. lyra and N. hennedyi in shape of axial area. Striae radiate, coarse, parallel to transverse axis Length 70–110μ. Distribution. Australia: Port Hacking. The following forms have been recorded previously as Naviculas; their generic affiliations will be indicated. N. affinis Ehr. var. undulata Grun. is Neidium affine var. undulatum (Petit, 1877). Lyall Bay. N. amphilepta Ehr. (Ehr., 1869). New Zealand. (= N. affinis). N. amphirhynchus v. Neidium amphirhynchus (Ehr.) Boyer. (Ralfs in Pritch. 1361). Australia. N. amphisbaena (is Caloneis amphisbaena. Ehr., 1869). New Zealand. N. apis Ehr. (is Diploneis adonis var. Oamaruensis Cl.). (Gr. & St., 1886. 322: A.S. 1890, 172, 7.) Oamaru. N. atomas (Naegeli) Grun., 1860. (Synedra atomas Nag. in Kütz., 1849.) (Østrup, 1910, 68.) Australia. N. (stauroneis) Australis (Grev.) (Grev. 1863c) type loc. Harvey Bay. (? = N. biformis Grun.) N. bacilliformis Grun. in Cl. & Grun., 1880. (Østrup, 1910; Boyer, 1927, 369.) Australia, New Britain. N. bacillum Ehr., 1854. (Østrup, 1910, 40.) Australia. N. biconstricta Gr. & St., 1887, 132 is a Diploneis. Oamaru. N. biseriata Petit, 1877 (non. Diploneis biseriata Cl.) (Petit, 1877.) Foveaux Strait (= Caloneis biseriata (Pet.) Cl.) N. campbellu Petit, 1877 (non N. campbellu Perag., 1915). (Petit, 1877, 22.) Campbell Island (Caloneis campbellu (Pet. Cl.) N. cancellata Donk., 1871. (Petit, 1877.) Foveaux Strait. N. capitata Ehr. (Ralfs in Pritch., 1861, 900). Australia. N. cardinalis Ehr. (Ralfs in Pritch., 1861.) Australia. N. cari? (Ehr., 1869). New Zealand (=N. cincta v. cari (Ehr.) Cl.)