342 \ii;u;t i!".\> PROM I hi. NATIONAL HERBABIUM. 



let. W Smith, Synop. Bril Dial. 1: 51. pi. 

 I \ I IX - k. I'.m 1 1 



[rish \\ ad. 11.2: 360. pi ;./. 10 [&' t 5 II I Smitl 

 Dial Typ. no. 243. L874. Brun, Diat. Up, 67. pi 1880 Van Beur. 



B81 [Yeat. Diat. 21 l. pi - • [Yu Inal. 



pan. Hist. Nat. 13: 343. pi. r./. 28. 18 n \. rh Zoo] 



Wien 10: 529. pi. I860 D< Toni, Syll Ml: 9 bum. 



s. lniii Phys. ftkon. Ges. Kdnigsb. 10: 88. pi. /../*. /. 18< 



1 m. Verb Zool. Bot. Gee. Wien 10: 540. pi 



Cleve unites A', amfr^ua Ehrenb., adding a question mark, and the same in Kttl 

 to the .il'<>\< I can see no reason for this. Ehrenberg's figui usual not 



uniform, but noneof them, noi his meager <l< scriptions, warrant theirunion with this 

 well-marked species The fact is thai a number of authors, mainly those cited above, 

 given toa variety of N.cuspidata having the general outline of BomeofEhren- 

 figun s, the name N. ambigua Ehrenb. The firsl definite figure and description 

 i- by W Smith 6 and many of the older diatomists have maintained thai the name 

 Bhould be credited to him, a procedure entirely oul of accord with modern 

 There is, however, no questii n thai his species bo well figured and described, belongs 

 here De Toni and Brun look upon the two as separate, bul Van Eleurck ami others, 

 while printing their figures and descriptions separately, Btate thai they are probably 

 alike. 1 have not only examined themany figures 1 n it a number of specimens of the 

 two, as II. I.. Smith's types, nos. 243 and 259, and find them to be only unimportanl 

 varieties. 



Cleve also groups here N. sphaerophora Km/.' The figure is a little suggestive 

 of thai Bpecies, bul il would be misleading to include this distinct diatom here. Sis 

 union of .Y. birostrata Greg, and'/ .V. quarnerensis Grun.< is a mistake, h is of inter- 

 esl thai both N. cuspidate and the variety called as above, N. ambigua, affaid fre- 

 <in<'ii! examples <>t' th<' internal craticular plates which were formerly known as 

 la, Craticula ehrenbergii, and Stictode&mis craticula. Good figures of 

 this Btructure are given by Van Beurck and by Heribaud. ' 



Pound at stal ion 3607, Bering Sea. 



^Navicula didyma Ehrenb.) Kiitz. Bacill. LOO. pi ',./. VII. 1-,'. pl.t8.f. 73. L844. 



Pritch. Hist. Enfus. ed. I. 893. pi 7./. 61; pi. 18. f. It. L861. Van Beur. Synop. 



90. pi. 9. f. 8-8. L881; Suppl.pl. B.f. 10. L885; Treat. Diat. 193. pi. 8./. 147. 1896. 



W. Smith,Synop. Brit. Diat. 1: bS.pl.17./. 184, Front./. CL IV. L853. Donk. 



Brit. Diat. 51. pi 7.f.8b noi ./'. Sa). L871 73. Rabh. Fl. Eur. Alg. 1: 203. L864. 



Schmidt, Jahresb. EComm. Deut. Meere 2: 85. pl.l.f.7a-b. I< s 7l. Schmidt. Atlas 



pllS.f.1-8. L875 (no! pl69.f.80,81 S9. L881 . O'Meara, Proc. Roy. Irish Acad. 



II. 2: 102 .mi p|. 88. f. ."' . L875. II. L. Smith, Sp. Diat. Typ. no. 265. 1874. 



DeToni, Syll. Alg. I; 71. L891. 

 Navicula Pinnulana) didyma Ehrenb. Phys. Abh. Akad. Wiss. Berl. 1839: 155. 



I s 1 1 . 

 Pinnularia didyma Ehrenb. Phys. Abh. Akad. Wiss. Berl. 1841: 383. pi .'. IV ./..;. 



pi. :.VI.f.r, pl.S. VII. i. 19(7). L843. Jan., Schles. Ges. Vaterl. Cult. 1862 J : 



28. pi ;l:.i. 18. L862. 



a Ktttz. Bacill. 95. pi. 18. f. 66. 1844. 

 MY. Smith. Synop. Brit. Diat. 1:51. pi L6./ 149. - 

 • ho,,k. Brit. Diat.34, pi. ■ >.!. 10. 1871 73. 

 <* Quart. Journ. Micr. Sci. 3: 10. pi I J. 18. 1855. 

 ' V-Hi. Zool.-Bot. Ges. Wien 10: 530. pl.8.f.8. I860. 



f Van Heur. Synop. pi It. J. 6. 1881; Treat. Diat.pl. \.f.l98. L896. Herib. hiat. 

 Auverg. pl.4.f. 18. L893. 



