man n im \ row Mi: \ I R< >SS V\ >\ \.i 333 



Small specimens of the presenl spe< i 



a Kiitz., a' variety of C. scutellum Ehrenb., the besi mark of d 

 being the round and widely sel beads of / . splendida and the more compa< 

 rectangular 1" . utellum. 



Pound at station 3696 f Honshu Island, Japan. 



NAVICULA Bory. 



Icula Bory, Encycl. Meth. d'Hist. Nat. 2: 562. L824. Ehrenb. Infus. L73 

 Kiii/.. Bacill. 88. L844. De Toni, Syll. Alg. 2:6. L891. W. Smith, Synop. Brit. 

 Dial 1: 16. 1853. Donk. Brit. Diat. 2. 187] L8 Heur. Synop. 71. 



Treat. Diat. 162 1896. Castr. Rep. Voy. Chall. Bot. 2: 22. 1886. Pritch. Hist, 

 [nfus. ed. 1. 892. L861. Rabh. Id. Eur. Alg 1- Ll - 1864. I leve Sv. Vet. Akad. 

 11. it. (11. 26-': 1. 136. 1894; 27 : 10. 1895. Cleve & Grun. Bih. Sv. Vet. A 

 II .n.ll. 17-: 27. 1880. Grun. Verh. Zool. Bot. Ges. Wien 10: 513. I860. Brun, 

 Diat. Alp. 63. 1880. 



ia Ehrenb. Ber. Akad. Wiss. Berl. 1840: 213. 1841. VV. Smith, Synop. 

 Brit. Diat. 1:54. 18 

 DipUmeis Ehrenb. Ber. Akad. Wiss. Berl. 1844: 84. 1845. I lev< . S> Vel Akad. 

 Ha n.ll. 26-: 76. 1894. 



a Ehrenb. Phys. Abh. Akad. Wiss. Berl. 1841: 134. L843. 

 ris Ehrenb. Phys. Abh. Akad. Wiss. Berl. 1841: 134. 1843. Kiitz. Bacill. 

 1844 De Toni, Syll. Alg. 2: 204. 1891. Van Heur. Treat. Diat. 158. - 

 /' . Rabh. in part; Grun. in Fenzl, Reis< Novara Bot. 1: 101. 



Dickieia Berk, in part; Van Heur. Synop. pi. />;./. 10. 1881; Treat. Diat. 233. 

 An > Pfitz.; Clev< . - V< t. Akad. Handl. 27 : 6. 1895. 



'■//// Pfitz. in Hanst Bot. Abhandl. 2: 39.1871. Cleve, Sv. Vet. Akad. Handl. 

 26-: 68. 1894. 



i leve, Sv. Vet. Akad. Handl. 26-': 16. 

 j Cleve, Sv. Vet. Akad. Handl. 27 : L23. 18 

 /' isi lia C. Au r . in part; Kiitz. Linnaea 8: pi. 13. f. 16. l v 

 rmbella C. Ag. ■' ■ Ehrenb.) in part; Consp. Dial v 



Ehrenb. in part: Kiitz. Bacill. 63. pl.S.f. 29. 1844. 

 Amp) Ihrenb. in part: Mikrog. pi. 3. I. f. 10-11, III. f. 5 



a in part; W. Smith. Synop. Brit. Diat. 2: 71. 1851 

 Breb. in part; W. Smith. Synop. Brit. Diat. 2: :• 



Kiitz. in part; W. Smith, Synop. Brit. Diat. 2:31. pi 

 W. Smith in part: Ehrenb. [nfus. 180. pi. 13. f. 10. Kiitz. Bacill. 102 

 no. 127, 128, etc. pi 



The enormous size-of this genus has incited many authors to attempt its division 

 upon more or less tenable grounds. Thus Ehrenberg divided it into Navicula i Bory 

 Ehrenb. and Pinnularia Ehrenb., the chief distinction being that the former had 

 smo >th. th" latter ribbed, valves. Bui the distinction was seen to be fictitious and 

 Kiitzing and Brebisson refused to accepl it. William Smith revived the names, 

 making the distinguishing feature the character of the striation, that in Pinnularia 

 being comp eed of smooth costae, while Navicula had the striae broken more or less 

 into moniliform or beaded lines. This would serve admirably to distinguish such 

 laria nobilis Ehrenb. froi ' Ehrenb. But two difficul- 



ties have stood in the way of making application of this distinction in general; first, 

 very few of the multitude of species in the genus can be positively classified by this 

 criterion, every conceivable gradal ion between plain or apparently plain i - 

 rows of independent beads being presented ; and, second, in even the extreme Pinnula- 

 ria type the apparenl presence or absence of perfectly smooth bars 

 a matter of illumination. It is true thai scientific elassifical hiefly valuable 



