'J K. OKAMURA. 



Area : Hongkong, Java, Shark's Bay (Australia), Arafura Sea. 



2. S.. Campana Castrac. Diat. Challeng. p. 88, t. 19, f. 14 ; De Toni, 

 Syll. Alg. II, p. 1138. PI VIII, fig. 2. 



S. Turris (Grev.) Grun. var. illustrated in Schmidt's Atlas Taf. 

 130, f. 42-43 much resembles the present plant from which it 

 however differs by having networks not diminishing as they 

 approach the edge of valve. 



Loc: Shinoshima (Prov. Owari). 



Area : Japan. 



Thalassiosira Cleve. 



3. T. gravida Cleve ? Gran in Brandt u. Apst. Nord. PL, Diat. p. 18, 

 f. 12 ; Gran Protophyta p. 28, PI. IV, f. 57-58. PI. VIII, fig. 3. 



Loc: Shirahama (Prov. Boshyu); Misaki (Prov. Sagami). 

 Area : Atlantic. 

 4 T. Nordenskioldii CI. Diat. Arct., p. 6, t. 2, f. 1 ; Gran Protophyta 

 p. 28, t. 4, f. 59 ; Gran in Brandt u. Apst. Nord. PL p. 16, f. 9. 



PI VIII, fig. 4. 

 Loc: Shirahama (Prov. Boshyu). 

 Area : Atlantic, Arctic Sea. 



Sceletonema Grev. 



5. 5. costatum (Grev.) Cleve Diat. W. Ind. Archip. p. 18 ; Gran in 

 Brandt u. Apst. Nord. PL p. 15, f. 7 ; Schiitt in Engler-Prantl Pflanzen- 

 fam. p. 63, f. 77. PL VIII, fig. 5. 



Loc: Prov. Shima ; Misaki (Prov. Sagami). 

 Area : N. Atlantic, Hongkong, Java, Peru. 



Araclmoidiscus Ehrenb. 



6. A. ornatus Ehrenb. A. Schm. Atlas t. 73, f. 4-6 ; Schtitt in Engler- 

 Prantl Pflanzenfam. p. 69, f. 95. PL VIII, fig. 6. 



Loc: Shirahama (Prov. Boshyu), Yokohama (Griind.). 

 Area : Tropical America, C. Good Hope, Hungary. 



Planktoniella Schiitt. 



7. P. Sol (Wallich) Schiitt in Engler-Prantl Pflanzenfam. I, lb, p. 72, 

 f. 103 ; Karsten Ind. Phytopl. p. 369, T. 39, f. 1-11; De Toni Syll. Alg. 

 II, p. 1424. PL VIII, fig. 7. 



Loc: Prov. Shima, Tosa. 



Area : Tropical and Subtropical Seas ; oceanic often deep-sea specis. 



