- 26 — 



There is no doubt that this species having two processes on each 

 valve belongs to the genus Cerataulina, and Cleve has also indicated 

 two in his figure 7 a, so that I do not understand his reasons for taking 

 it as a Rhizosolenia. 



2 (rr) - 3 (+). 



Area: Red Sea, Malay Archipelago. 



Hemiaulus Ehbg. 



73. H. chinensis Grev. Ann. Magaz. Nat. Hist. XVI, p. 5, PI. 5, f. 9, 



1865; H. Eeibergii Cleve, Diat. f. the Sea of Java, 1873, p. 6, PL 1, f . 7 ; 

 Leuduger-Fortmorel, 1. c. p. 41; Cleve, Pl. f. the Red Sea, p. 1033; PI. f. 

 the Indian Ocean and the Malay Archip. p. 21; Atl. Plankton Organisms 

 p. 329. 



Professor Cleve informs me in a letter that his II. Heibergii is 

 identical with H. chinensis of Greville. 



6 (it) - 10(4-)- 



Area: Tropical Atlantic Ocean, Red Sea, Indian Ocean, Malay Archipelago, 

 Arafura Sea, Japan and China Seas. 



B. Pennatae. 



Fragilarieae. 

 Thalassiothrix Cleve & Gr un. 



74. T. Fraunfeldii G run. in Cleve & Grunow, Arctische Diatomeen, 

 K. Sv. Vet. Akad. 17, No. 2, 1880, p. 109; de Wildeman, 1. c. p. 104; 

 Castracane, Challenger Report p. 54— 55, Pl. XIV, f. 1, 8 (incl. T. curvata 

 Castr., Pl. XXIV, f. 6) ; Schröder, Neapel p. 31 ; Cleve, Phytoplankton p. 25; 

 Atl. Plankt. Organisms p. 356; Ostenfeld & Schmidt, Pl. f. the Red Sea, 

 etc. p. 162; Van Heurck, Synopsis PI. 37, f. 11— 15; Asterionella Fraun- 

 feldii Grunow, Verh. zool.-bot. Gesellsch. Wien 1863, p. 140, PI. 14, f. 18; 

 Cleve, Diatoms of the Sea of Java 1873, p. 12. 



I should think that all the specimens belong to the var. javanica 

 Grun. in Van Heurck, 1. c. f. 13. 



1 (+) - 2 (r) - 3 (rr) - 6 (r) - 7 (r) - 10(+). 



Area: Atlantic Ocean, Mediterranean, Red Sea, Indian Ocean. Malay Ar- 

 chipelago, China Sea, Japan Sea, Pacific Ocean. 



75. T. longissima Cleve & Grunow, I.e. p. 108; Ostenfeld & Schmidt, 

 PI. f. the Red Sea, etc. p. 162 (f. gracilis Ostf.); Cleve, Phytoplankton 

 p. 25; Atl. Plankt. Organisms p. 357 ; PI. f. the S. Atlantic and the S. 

 Indian Ocean p. 935; PI. f. the Red Sea, p. 1035; PI. f. the Indian Ocean 



