21 



This species belongs to the subgenus Phaeoceras Gran, which has 

 numerous small chromatophores, also in the awns. 

 10 (r). 

 Area: Red Sea, Malay Archipelago, South China Sea. 



57. C. Schiiiidtii Ostf. in Ostenfekl & Schmidt, Plankt. 1". the Red 

 Sea, etc. p. 155, f. 8; ?C. Weissflogii Gleve, PI. f. the Indian Ocean and 

 the Malay Archip. p. 15 and p. 55, non Schiitt. 



This species which 1 have described from the Red Sea, occurs also 

 in the Gulf of Siam; and I suppose that it is the same which Gleve 

 1. c. has identified with C. Weissflogii with hesitation. 



10 (r). 



Area: Red Sea, Malay Archipelago (?). 



58. C. seciindiini Gleve, Diat. f. the Sea of Java 1873, [). 10, PI. 11, 

 f. Ua, b; Leuduger-Fortmorel, I.e. p. 37; de Wildeman, I.e. p. 134; Van 

 Heurck, Synops., PI. 82, f. 5; C. curvisetum Gleve, PI. f. the Ind. Ocean 

 and the Malay Archipelago 1902, 



p. 1 8 and p. 55, n o n Gleve, in 

 Kanonbaaden Hauchs Togter, Kjo- 

 benhavn, 1889, p. 55 with fig. 



Professor Gleve supposes 

 (in his last paper (I.e. 1902, p. 55)) 

 that the Indian C. secundum is 

 the same as C. curvisetum from 

 the Temperate Atlantic, but I can 

 not enter upon this opinion, as 

 the spores of C. secundum figured 

 by Gleve himself (1873, PI. II, 

 f. 14 a) are rather different from 

 the spores of C. curvisetum (see 

 Gran, Protophyta, PI. II, f. 22). 



i2 (rr) - 8 (r) - 4 (rr) - 5 (rr) 

 — 6frr) - 10 (r). 



Area: Malay Archipelago. 



59. C. siainensc Ostf. n. sp. 



Chains straight, about 50 /^ 

 broad; valves circular; fora- 

 mina lanceolate; hoop at least 

 a third part of the cell; chro- 

 matophores two, close to the 

 valves; awns all alike, rather 

 robust , undulated ; the one 

 about in the sagittal plane, the 

 other diverging at a nearly 



Fig. 17. Chaetoceras siamense Ostf., 



right angle. 



soo. 



Chain in front view, cell in side view {-^) 



