THE BOTANICAL MAGAZINE. [Vol. xxi. No. 244. 



Fig. 45 a measures 6 u in thickness. It will be seen from the 

 figure just mentioned that all the horns stand on sagittal-longi- 

 tudinal plane. 



Section 7. Constricta Ostf. 



15. C. constrictum Gran. PI. IV, Fig. 64 a-b. 

 Gran, Diat., 1905, p. 80, Fig. 96.— Lemm. Ergebnisse, 1899, 



p. 385. 



Loc. in Jap. : 40 miles off the coast of Shinshirijima (Kurile). 



If my identification proves to be correct it seems to me that 

 C. constrictum is very difficult to distinguish it from C. siamense. 



In the specimen represented in Fig. 64 a, the breadth and 

 thickness of the bod} r measure 26 <i and 15 fJ. respectively, and 

 the height of foramen, 7.5 u. 



16. C. javanicum Cleve. PL IV, Figs. 55 and 55 a, b. 

 Cleve, Java, 1873, p. 10, PI. II, f. 13 ; Ostf. Mar. PL Diat., 



1902, p. 236, Figs. 14, 15. 



Loc. in Jap. : Cape Goza in Prov. Shima (Aug., 3, 1904) ; 

 Tateyama in Prov. Boshyu (June, 2, 1906). 



This species is, as Cleve has already stated, nearly akin to 

 C. Schuttii CL and C. affine, Lauder, but to me it seems not to 

 be identical. In this species, apical horns are more or less acute 

 in divergence and often run almost parallel to each other. The 

 horns which have a characteristic curvature as shown in Figs. 

 55 a, h are thin and turn off toward the ends of chain. 



17. C. Vanheurcku Gran. ? PL III, Figs. 21, 22. 

 Ostf. Mar. PL Diat., 1902, p. 240, Figs. 18, 19. ? 



Loe. in Jap. : Shirahama in Prov. Boshyu (May, 1904). 



The specimen before us may not belong to the species men- 

 tioned, as I was ignorant of the character and number of chro- 

 matophores in the present plant. 



Section 8. Stenocincta Ostf. 



18. C. athnc Lauder. PL III, Figs. 4, 5. 

 Lauder, Hongkong, L864, p. 68, PL VIII, f. 5. 



