1913- ^O- 8- JAPANESE DIATOMS. I9 



?= C. pelagicum Cleve: 1873 a, p. 11, PI, i, fig. 4. — Osten- 

 feld: 1903, p. 574. — Gran: 1906, p. 83, fig. loi. — Schrö- 

 der: 1906, p. 336. 



Ostenfeld reported CJi. distans Cleve from the material collected 

 both in the Gulf of Siam and in the Red Sea; but the plant he has 

 delineated (1902, fig. 13) seems to belong to this species as is shown by 

 the parallel suture-lines of the girdle-band. 



A species closely connected with CIi. hiciniosum is Ch. OstenfeUUi 

 Cleve. The latter, however, according to Cleve's own view, should be 

 identical with his old, incompletely-described species Ch. pelagicum. If 

 this identity could be proved, it might be right to unite these form 

 under the old name, Cli. yelagicimt. We choose the name proposed by 

 ScHLTTT, however, as the earlier one is by no means exactly defined. 



Schröder reports Cti. pelagicum Cleve from the sea off the mouth 

 of the Yang-tse-Kiang, but without any comment. 



Loc. Yeddo Bay; Volcano Bay; Misumi (Yendo). 



Chaetoceras breve Schutt. 



Schutt: 1895, p. 38, t. 4—5, fig. 4 a — b. — Gran: 1900 b, 



p. 121. — Ostenfeld: 1901, p. 295, fig. 6. — Do.: 1902, p. 233, 



fig. 10. — Gran: 1906, p. 83, p. 100. — Schröder: 1906, p. 337. 



= C. didgmum var. hiemalh Cleve: 1897 ^» P- 21, t, i, fig. 18. 



= C. hiemale Cleve: 1900 b, p. 25, fig. 9. 



Comparing the specimens which Yendo reported from Volcano Bay 



as C. breve Schutt, with the Atlantic specimens, we find certain difficulties 



in the identification. The Volcano Bay specimen is sterile, and resembles 



both C. diadema (Ehr.), and C. debile Cleve, as also C. laciniosum 



Schutt in several respects. It is, however, provided with terminal liorns, 



which have hitherto never been found in the Atlantic form of C. debile 



Cleve. It is also distinguishable from C. laciniosum by having single 



chromatophores. The setae are short and slender, and all curve towards 



the sagittal plane, Resting-spores are needed for a conclusive determination. 



Schröder also mentions the present species from the collections at 



Enoshima and at Akashi, Whether his specimens were provided with 



spores or not, is not mentioned in his paper. 



Loc. Volcano Bay (Yendo). Enoshima; Akashi (Schröder). 



Sect. 10. Diadema Ostenf. 

 Chaetoceras diadema (Ehr.) Gran. 



Gran: 1897 a, p. 20, PI. 2, figs. 16— 18. — Do.: 1906, p. 84, 

 fig. 102. — Schröder: 1906, p, 337. — Meunier: 1910, p, 232, 

 PI, XXVI, figs, 15 — 23. — Yendo: 191 1, p. 26. 



