155 307 
The longitudinal plication is not of equal height through its whole length 
but lower near the apices and in the middle so that two lateral elevated 
spots arise giving this form a very characteristical appearance. The de- 
cussate striation is only conspicuous on the elevated parts. 
KKt, KCgN, KMn—CLt (8 samples). 
Apiculate Grun. 
239, N. marginulata Grun. V.H. Syn. tab. LVIII, fig. 13. 
KKm, KKt (2 samples). 
Area: Kara, Europe, Between Aden and Bab el Mandeb, Malay Archipelago, 
Borneo, Samoa. 
— — var. didyma Grun. V. H. 1. c. fig. 14. Perag. Diat. de Fr. 
tab. LXX, fig. 16. 
KKt, KMn KMn—CLt (4 samples). 
The specimens met with have a length of c.0,04mm. and are very 
finely striated; I therefore suppose, that they belong to Grunow’s forma 
minuta (Cl. & Grun. Arct. Diat. p. 73). 
Area: var. didyma: widely distributed. 
forma minuta: Tonga Islands, Samoa, Antilles (Grunow l.c.). 
Pseudo-Tryblionella Grun. 
240. N. acuta Cl. Cl. West Ind. tab. Ill, fig. 20. 
Found only in a sample without habitat. 
Area: Antilles, Tonga Islands, Samoa. 
The present form is a little more rounded at the apices than shown 
in Cleve’s figure. 
941. N. alata Leud. Fortm. Leud. Fortm. La Mal. tab. II, fig. 11. 
KKm (2 samples). 
Area: Java. 
Bilobate Grun. 
242. N. bilobata W. Sm. var. minor Grun. V.H. Syn. tab. LX, fig. 2. 
LN (4 sample). 
Area: Brazil, Europe, Society Islands. 
243, N. Jelinecki Grun. Perag. Diat. de Fr. tab. LIX, fig. 19. 
KKt, s.1. (2 samples), 
Area: East India, Malay Archipelago. 
In two samples (KKt & s.1.}.I found a Niteschia, exactly agreeing 
with N. formica Hantzsch (H. Ost. Archip. tab. VI A, fig. 8).. 
In CL. & Grun. Arc. Diat. p. 74 Grunow points out that the figure 
20* 
