1913- ^O- 8. 



JAPANESE DIATOMS. 



Loc. Var, geniiina: Tosa Prov. (Okamura). Misumi (Yendo). Enoshima; 

 Akashi (Schröder). 



Var. anglica: Shima Prov. (Okamura). Misaki; Misumi (Yendo). Enosh- 

 ima; Formosa Channel (Schröder). 



Var. protuberans: Shima Prov. (Okamura); Misaki; Otaru Bay; Misumi 

 (Yendo). 



Sect. 7. Constricta Ostenf. 

 Chaetoceras constrictum Gran. 



Gran: 1897 a, p. 17, PI. i, figs. 11 — 13, PI. 3, fig. 42. — Do.; 

 1906, p. 80, fig. 96. — Okamura: 1907, p. 96, PI, 4, fig. 64a, b. 

 Neither Okamura's description nor his ilhistrations give any inform- 

 ation with regard to the spores. Nor do the figures he has given show 

 the characteristic marked constrictions on the girdle. We have not seen 

 any specimen of the species in our Japanese material. 

 Loc. Off the Kuriles (Okamura). 



Chaetoceras Van Heurckii Gran. 



Gran; 1897 a, p. 18, 

 — Ostenfeld: 1902, 

 p. 61, fig. 18. — Oka- 

 mura: 1907, p. 96, PI. 

 Ill, figs. 21 & 22. — 

 Schröder: 1906, p. 



337- 



= r. lîalfsii Van 



Heurch 1880—85. PI. 



82 bis, fig. 3. 



The present species 

 is characterized by having 

 pallisade-spines on the 

 margin of the secondary 

 valve of the resting-spores. 

 Ostenfeld referred to it a 

 specimen from the Gulf 

 of Siam, which had the 



pallisade-spines on the Fig. 6. Chaetoceras Van Heurckii Gran. 



r t_ ..1 (J- Terminal portion of a chain. X 360. 



margms ol both primary , . ^ 



^ ^ ^ b. A spore. 



and secondary valves (1. c., Drawn from Cleve and Möllers Diat. No. 307. 



