31 249 
L. 0,04 mm., B. 0,007 mm. 
Valve narrow lanceolate, attenuated towards the apices. Central 
pores distant. Strize fine, at right angles to the apical axis. By 
slighter enlargement the striation, especially in the central part 
presents an irregular longitudinal undulation, nearly as in Ano- 
moeoneis. 
This form probably must be referred to N. cusp.; it is nearest 
to var. lanceolata. 
Solitary in two samples from Klong Prao and Lem Dan. 
Area: Nav. cusp. lanc.: El Kab. 
14. N. Stodderi Green]. var. insignis Grun. Cl. Syn. 1, tab. Ill, fig. 13. 
Solitary in two samples from Lem Dan. 
Area: Bengal. 
Mesoleje Cl. Syn. I, p. 127. 
15. N. Pupula Ktz. V.H. Syn. tab. XIII, figs. 15—16. 
Lem Dan (7 samples). 
Area: ubiquitous. 
Bacillares Cl. Syn. I, p. 136. 
16. N. Pseudobacillum Grun. V.H. Syn. tab. XII, fig. 9. 
Solitary in a sample from Lem Dan. 
Area: Europe, Japan, Australia, New Zealand. 
Lineolate Cl. Syn. II, p. 10. 
17. N. eryptocephala Ktz. var. exilis Ktz. V.H. Syn. tab. VIII, fig. 2. 
Lem Dan (3 samples). 
Area: Europe. 
18. N. radiosa Ktz. var. tenella Bréb. V.H. Syn. tab. VII, figs. 21—22. 
Klong Majum, Klong Sarlakpet, Lem Dan. (5 samples). 
Area: Greenland, America, Europe, Japan, Tasmania, Australia. 
19. N. eineta Ehr. var. siamensis Ost. var. nov. tab. nostr., fig. 5. 
L. 0,036—0,05 mm., B. 0,006—0,007 mm., strive 20 in 0,01 mm., 
finely transversely lineated. 
Valve narrow lanceolate, somewhat attenuated towards the 
apices. Strie in the middle radiate, alternately longer and shorter, 
towards the apices convergent. Central area narrow. 
Klong Majum, Lem Dan. 
1 have considered this form a variant of N. cincta Ehr., although it 
differs somewhat in its outline and in its closer strie. Possibly it is 
nearer to N. Bottnica Grun. (V.H. Syn. tab. VII, fig. 33). 
