Lo 
iN) 
is) 
bs 
2(rr) — 6 (rr). 
Area: Found in all the Oceans, mostly along the coasts. 
6. (. Janischii A. Schmidt, Atl. d. Diat. Kunde, Pl. 64, f. 3, 4. 
Rattray, Coscinodiscus, p. 543 and v. arafurensis p. 544; Grunow, Denksch. 
d. Wiener Akad. d. Wissensch. 1884, p. 76; C. arafurensis var. nov. Castr., 
Challenger Report, Botany, Vol. II, 1886, p. 153, Pl. 2, f.4; C. craspedo- 
discus Castr. ibid. P].3, f.5; C. Janischii Cleve, Pl. f. the Indian Ocean 
and the Malay Archip. p. 20. 
3 (rr) — 10 (rr). 
Area: Gulf of Bengal, Malay Archipelago, Arafura Sea. 
7. €. nobilis Grun., Journ. Roy. Microsc. Soc. 1879, p. 687, Pl. 1, 
f.1; Leuduger-Fortmorel, |. c. p.45; Rattray, Coscinodiscus, p.545; Cleve, 
Pl. f. the Ind. Ocean and the Malay Archip. p. 20 and p. 56; C. papuanus 
Castr., Challenger Report p. 154, PI. 3, f. 3. 
The form observed resembles very much C. papuanus Castracane 
l.¢.; it is about 250—300y in diameter; and I am following Professor 
Cleve in regarding C. papuanus as a form of C. nobilis. 
3 (+) — 10(rr). 
Area: Great Britain. Gulf of Guinea, Malay Archipelago, Arafura Sea, 
South China Sea. 
8. ¢. oculus ividis Ehbg., Abhandl. Berl. Akad. 1839, p. 147; C. 
centralis var. nov., Castr., Challenger, Pl. 2, fig. 3. 
A form which agrees very well with the that figured by Castracane 
l.¢., was found sparingly in one of the samples. 
3 (rr). 
Area: Found in all Oceans. 
9. G.radiatus. Ehbg., Abhandl, Berl. Akad. 1839, p.148, P13, f. Lac. 
Forms, which I refer to this species, were found rather sparingly in 
most of the samples. 
A(r) — 38(rr) — 4(rr) — 6 (rr) — 7(@r) — 10(rr) 
Area: Found in all Oceans. 
Palmeria Grev. 
10. P. Hardmaniana Grev., Van Heurck, Treatise on the Diatomaceae 
1896, p. 538, f. 286; Cleve, Pl. f. the Indian Ocean and the Malay Archip. 
p. 22 and p. 56. 
The interesting form of which I have given some figures, belongs 
to. the genus Palmeria and 1 prefer identifying it with the only known 
species P. Hardmaniana, although the figure by Van Heurck is rather 
different. My specimens are very delicate, 500—650 w long and 250— 
