24 H. H. GRAN AND K. YENDO. M.N. Kl. 



Sect. 15. Socialia Ostenf. 

 Chaetoceras sociale Laudkk. 



Lauder: 1864, p. jy, PI. 8, fig. i. — Cleve: 1896a, p. 9, 

 PI. 2, fig. 9. — Gran: 1897a, p. 26, PI. 4, fig. 54. — Do.: 1906, 

 p. 96, fig. 123. — Schröder: 1907, p. 337. — Meunier: 1910, 

 p. 249, PI. XXVII, figs. 33 — 36. — Yendo: 191 i, p. 26. — 

 Okamura: 191 1, p. 7, PI. XI, fig. 30. 

 ? = C. Wighann Cleve et Grunow: 1880, PI. 7, lig. 134. 



= C. Lorenzianum var!'' parvum Grunow: 1880, pi. 7, fig. 138. 



? = C furceUatum Yendo: 191 i, p. 26. 



The directions of the four setae from a frustule are quite peculiar 



to the species, as has been well illustrated by Cleve, 1. c, fig. g b. C. 



furcellatuni Bail., reported by Yendo from Volcano Bay, is probably 



based on a form of the present species. 



Loc. Boshu Prov. (Okamura). Volcano Bay; Misaki; Otaru Ba}^ 

 (Yendo). Enoshima; Akashi (Schröder). 



Sjjecies duhiœ. 

 Chaetoceras hispidum Brightw. 



Brightwell: 1856, PI. 7, fig. 37- — 



= Goniotheciuni liispidum Ehrenberg: 1844, p. 82. — Do.: 

 1854, Taf. 18, fig. 107. — Janisch: 1861, p. 26, Taf. i A, fig. 35. 

 — KiJTziNG: 1849, P- 23- 

 We found isolated spores in the material from Misumi, which exactly 

 accord with the figure delineated by Brightwell in the above-mentioned 

 work. To which species of Chaetoceras they belong, still remains doubt- 

 ful. Van Heurck's figure (Synopsis, PI. 82, bis. fig. 5) of C. Jiispi- 

 dum has short spines on the secondary valve. 

 ciiiiiSÖMö This is not the case in Brightwell's figure, nor 



in our specimen. 

 Fig. 14. Chaetoceras We simply state the occurrence of the above- 



Inspidimi Brightw. mentioned form in southern Japan, and reserve it 

 A spore ; drawn 



from burnt prépara- ^^r future study. 



tion. X 360. Loc. Misumi (Yendo). 



Chaetoceras japonicum Ehr. 



Ehrenberg: 1872, p. 124. 

 This species, as far as we are aware, has not been mentioned in 

 the literature since its description was first published by Ehrenberg. 

 Loc. Japanese sea (Ehrenberg). 



