C. H. Ostenfeld: A List of Phytoplankton from the Boeton Strait, Celebes. J5 



C. commulatiis Grun., as far as the North Sea form is concerned, 

 is not identical with C. Jonesianus (Grev.) (but it is probable that 

 Grunow has included both under the one name). Now it seems to 

 me convenient to keep Greville's name for the tropical form with 

 the »minute« structure (Greville's specimen came from a »guano; 

 locality unknown«) and Grunow's for the North Sea form. The 

 synonymy of the first is given above, that of the last is as follows: 

 C.commutatns Grun., Denkschr. Wien. Akad., 1884, p. 79, ex maxima 

 parte; Brockmann, 1. c, 1914, p. 43, fig. 5; C. concinnus, var. Jone- 

 sianus Van Heurck, Treatise Diatomac, 1896, p. 531, ex maxima 

 parte; C. biconicus Van Breemen, 1. c, 1905, p. 23, fig. 5; Ostenfeld, 

 1. c, p. 148, pi. 6, figs. 1-3. 



In a Key to identify the species of the Biapiculati which I have 

 published in the above quoted paper (1908, p. 148) the section Ba 

 (which contained only C. biconicus) has to be altered thus: 



B. Girdle band equally broad everywhere. 



a. The two asymmetrical apiculi very large. 



a, structure coarse; cell medium sized. C. commutatus 



Grun. 

 |3, structure fine; cell large. C. Jonesianus (Grev.) nob. 

 The chromatophores of C. Jonesianus are numerous and rather 

 large, as seen in my figure (Fig. 7). The angle between the two 

 large apiculi is about 100°. 



C. radiatus Ehbg., Abhandl. Berl. Akad., 1839, p. 148, pi. 3, 

 fig. 1. 



Under this collective name I place some rather small coarsely 

 areolated Coscinodisci which were not rare in the sample. 



C. Rothii (Ehbg.) Grunow, Denkschr. Wien Akad., 1884, p. 29, 

 tab. 3, fig. 20. 



A rather small Coscinodiscus species (ca. 90 u.), which agreed 

 well with Grunow's figure, was found rarely in the sample. 



C. undulans Rattray, 1. c, p. 104; C. undulatus Castracane, 

 Challenger Rep., p. 159, tab. 8, fig. 3; non C. undulatus Cleve. 



Fragments of a large species with undulated valves and very 

 large areoles were not rare in the sample. It seems to agree well 

 with Castracanes's above quoted figure of his new species, which 

 came from the Pacific. 



Detonula Moseleyana (Castr.) Gran, Nyt Magaz. Naturv. 1900, 

 p. 113; Lauderia? Moseleyana Castracane, 1. c, p. 90, pi. 24, fig. 9. 



Drawn by Dr. Justesen. 



D. Schroederi (Bergon) Gran, Diatom, in Nord. Plankton, 1905, 

 p. 22; Lauderia Schroederi Bergon, Soc. scientif. d'Arcachon, Stat, 

 biolog., 6 e année, 1902, p. 69, pi. 1, figs. 11-15; B. Schroeder, Viertel- 

 jahrsschr. Naturf. Ges. Zürich, 51, 1906, p. 344, fig. 4; G. Karsten, 

 Deutsche Tiefsee Exp. 1898-99, Bd. 2, Teil 2, 1906, p. 375, pi. 41, 

 fig. 10. 



Drawn by Dr. Justesen. 



To this species I think it better to refer the Detonula from the 

 Gulf of Siam which in my report (Bot. Tidsskr., 25, 1902, p. 225) 

 I have called D. delicatula (Perag.) Gran. 



