— 12 — 



l(rr) - 2(r) - 3 (+) — 4 (rr) - 6 (r) - 7 (rr) - 10 (+). 

 Area: Tropical Atlantic, Mediterranean, Red Sea, Gulf of Aden, Malay 

 Archipelago, South-Indian and Pacific Oceans. 



31. R. robusta Norman, Pritch. Infus. 1861, p. 866, PI. 8, f. 42; 

 Leuduger-Fortmorel, 1. c. p. 36 ; Cleve, Diat. f. the Sea of Java, 1873, p. 1 1 ; 

 Gastracane, Challenger Rep., PI. 24, f. 5; Peragallo, Monogr. Rhiz., p. 109, 

 Pl. II, f. 1, la, PI. III, f. 1, 2; Cleve, Phytoplankton, p. 25; Atl. Plankt. 

 Organisms, p. 345 ; PI. f. the Red Sea p. 1034 ; PI. f. the Indian Ocean 

 and Malay Archip. p. 23; Schröder, Neapel p. 25; Ostenfeld & Schmidt, 

 Pl. f. the Red Sea, etc. p. 161. 



1 (rr) — 2 (rr) - 3 (rr) — 6 (rr) — 8 (rr) — 10 (rr). 



Area: Tropical Atlantic Ocean, Mediterranean, Red Sea, Indian Ocean, 

 Malay Archipelago, Pacific Ocean. 



32. R. setigera Btw., Microsc. Journ. 1858, p. 95, PL 5, f. 7: Van 

 Heurck, Synops. PI. 78, f. 6 — 8; Peragallo, Monogr. Rhiz. PL 4, f. 15, 16, 

 non f. 12 — 14; Hensen, Fünfter Ber. Komm. Deutsch. Meere in Kiel, 1887, 

 PL V, f. 38a, b, c; Cleve, Fish. Board for Scotland 1896, p. 301, f. 12; 

 Grunow, Novara Exp. p. 28; Cleve, Diat. f. the Sea of Java p. 1 1 ; Atl. 

 Plankt. Organisms p. 347 ; PL f. the Ind. Ocean and the Malay Archip. 

 p. 23; Ostenfeld & Schmidt, Red Sea, p. 171 ; Lemmermann, 1. c. p. 317; 

 Leuduger-Fortmorel, 1. c. p. 36; de Wildeman 1. c. p. 123; R. japonica 

 Gastr., Challenger p. 72, PL 23, f. 7. 



The specimens are rather thin and delicate, about 8 — 10 fx broad. 

 l(r) - 2(rr) — 6 (rr) - 7 (rr) - 10(+). 



Area: Atlantic Coasts of Europe and North of S.America, Mediterranean, 

 Red Sea, Indian Ocean, Malay Archipelago, Japan Sea, Pacific Ocean. — Neritic 

 species. 



33. R. Shrubsolii Cleve, New Diatoms, 1881, p. 26; Van Heurck, 

 Synopsis, PL 79, f. 1 1 — 13 ; Peragallo, Monogr. Rhiz. p. 114, PL 5, f. 8, 9 ; 

 Cleve, Phytoplankton p. 25 ; Atl. Plankt. Organisms p. 347 ; PL f. the Red 

 Sea, p. 1034; PL f. the Ind. Ocean and Malay Archip. p. 23 ; Schröder, 

 Neapel p. 26; Ostenfeld & Schmidt, PL f. the Red Sea, etc. p. 161; 

 ?JR. atlantica Peragallo, Monogr. Rhiz. p. 114, PL 5, f. 4 — 5. 



2 (rr) — 6 (rr) — 10 (rr). 



Area: Atlantic Ocean in the Eastern part from the Færoes southwards, 

 Mediterranean, Red Sea, Gulf of Aden, Indian Ocean, Malay Achipelago, Yeddo 

 Bay. 



34. R. Stolterfothii Perag., Diat. de Villefranche, p. 90, PL 6, f. 44; 

 Monogr. Rhiz. p. 108, PL 1, f. 17, 18; Cleve, Phytoplankton p. 25; Atl. 

 Plankt. Organisms p. 348; Ostenfeld & Schmidt, PL f. the Red Sea, etc. 



