N. liiiiiwrosii HiiÉu. 

 Brkb. ill \V. Sm. Hiit. Dirtt. 11. p. «Ki. Van llKincK Synops, p. 98, \,\. XI, f. 20. 



Very rare: Kat'tsuiKl r. 



])it>tribidion : Coasts of the North iSea. Baltic. Arctic re- 

 <rions. Tlie Mediterranean, Bhick Sea, Caspian JSea. The Red 

 Sea; Indian Ocean. Sidney. Cameroon. 



N. monilifera Cl. 



('L. 1. 0. p. 4;J. -Y. grautthta Brkb. in Bonk. Jlicr. .Jonni. VI. p. 17. pi. 111. 

 f. 19. non X. iirntuilatn Bail. 



Very rare: Tlie Ostnc^tiord r. 



Tar. heterosticba ('i,, 

 ('L. 1. c. .V. ijramdata A. Scum. Atlas, pi. (j, figs. 15—1(3. 



Very rare: Raftsund, r. 



Dhtfrihidion (of the main species): North Sea. Ceylon. 

 Madagascar. The var. only known from Hungary, fossil. 



iV. latissinia Gueo. 

 Greg. Jlior. Jouvu. IV, p. 40. i.l. V. fi-s. 4, 4*. A. Sciui. Xords. Dial. pi. 1, f. 30. 



Frequent: Moskenstrommen r +, Svolvier r, the Ostnestiord r, 

 Raftsund r, Steue r +. 



Disiribution: Coasts of the North Sea. Finmark. The Me- 

 diterrauean. Black Sea. Indian Ocean. Pacific Ocean. 



N. punctnlata W. Sm. 

 "\V. Sm. Brit. Diat. I, p. hi. pi. Hi. t'. Inl. Van Heukck Synops, p. 98, pi. II, f. 16. 



Very rare: Stamsund r. 



Distribution : Coasts of the North Sea. Arctic regions. The 

 Mediterranean. Caspian Sea. America. Indian Ocean. 



iV. frandulenta A. Schm. 

 A. Schm. Atlas pi. 70, f. 60; Xonl^. Diat. pi. Ill, f. 18„ (witliout name). 



Rare : Stamsund r -f . Many specimens. 

 DistyUxition : North Sea. Sebastopol. 



c. Lineolatæ ci. I. c. 11. p. 10. 

 Radiate or parallel striæ, transversely lineate. 



A", mdiom Kutz. 



KuTZ. Bacill. p. 91. pi. IV, f. 23. Van Helrck Synops, p. 83, pi. 7, f. 20. 



Incl. Plnmdaria acuta \V. Sm. Brit. Diat. I, p. 56, pi. XVIII, f. 173. 



Rare: Stene, r. 



Distribution: Frequent fresli water species, especially in Nor- 

 thern and "Western Eui'ope. .\sia. Africa, America. 



iV. per e grina Kiirh. 

 Ehrb. Ami. p. 1:33. pi. l.;, fi^s. 5—6. A. Scum. Atlas pl. 47, figs. 57—60. 



Veiy rare: Gaukværo, r. 



Distribution: Brackish water. Coa.sts of the North Sea. Bal- 

 tic. Adinatic Sea. Arctic regions. America. Pacific Ocean. In- 

 dian Ocean. 



var. kcfwinHi'iisis (Kiium.) ('l. 



L. 1. c. p. 18. Viniiitlarid k. Kiirb. Itfil Ak. 1840, ii. 20. Sarkula k. 



A. Scum. Atlas pl. 47, fij;s. (il- 62. 



Very rare: Svolvæi'. 141 |). loni:'. 

 Distribution: lirackisli water: Scotland. 



A''. digito-riKliata (liitEii) A. Scum 



A. Schm. Nonls. Diat. p. 92, pl. Ill, l'. 4. I'imiidaria d. GiiKrj. Jli.r. ,},,urn. 



IV. pl. 1, f. 32. 



Frequent: Stamsund -f, Svolv;er r, the Ostncsfiord r, Stene r. 

 Distribution: Coa.sts of the North Sea. Arctic regions. Ca.s- 

 pian Sea. New "S' ork. 



N. directa W. Sm. 

 W. Sm. Biit. Diat. 1, p. 56, pl. 18, f. 172. A. Schm. Atlas pl. 47, figs. 4—5 



(rar. ijenu'ma Cl. 1. c. p. 27). 



Rare: Stamsund r +, the Gstuesfiord r, Stene r. 

 Distribution: Coasts of the North Sea. Arctic regions. Yokohama. 



var. reuiota finiN. 

 I Grun. in C'L. et Grcn. Avet. Diat. i,. 39. A. ScHM. Noids. Diat. p!. Ill, f. 2. 



Somewhat rare: Stamsund -f, the Ostnesfiord r, Gaukværo r. 

 Distribution: Coasts of the North Sea. Arctic i-egions. The 

 Mediterranean. Red Sea. Central America. 



var. siibtilis (Greu.) Cl. 

 Cl. Vega p. 467. Pinindaria s. Grei;. Diat. of Clyde, p. 488, pl. IX, f. 19. 



Rare : Stene r, Gaukværo i'. 

 Distribution: Scotland. Ai'ctic reo-jons. 



N. fintuarchica (Cl. et CiRUN.) Cl. 

 Cl. 1. c. p. 28. Stawnneh f. Cl. et Grun. Arct. Diat. p. 47, pl. Ill, f. 63. 



Very rare: Stone, rr. Vei'y similai' to the figure quoted, 

 though -wanting the fainter or blank lateral areas. Also very 

 similar to A", tnnisiiuns forma miiiutu Cl. Vega pl. 36, f. 37. 



N. frigida Grcn. 



Grun. in Cl. et (tRIX. Aict. Diat. p. 39. Grin. Diat. Franz Jos. Land. p. 103, 



pl. I, f. 25. Xaviada kaiinna r. frigida Cl. 1. c. p. 28. 



Probably derived from the plankton. 



Rare: Stamsund, r^-. 



Distribution: Arctic regions. Cf. above p. 10.5. 



N. cancellata Donk. 



DONK. Brit. Diat. p. -55. pl. 8. fi<;s. 4 a. b. A. Schm. Xords. Diat. pl. II, 



rigs. :36--37. 



Very variable, probably also including A. zostrrcti and N. north- 

 umbrica. 



Very frequent: Moskenstrommen -f. Stamsund -|-, Svolvær -f, 

 the Ostnesfiord +, Raftsund r, Stene + c, Gaukværo cc. 



Distribution: Coasts of the North Sea. Baltic. Arctic re- 

 gions. The Mediterranean. Indian Ocean. Pacific Ocean. Ker- 

 guelen. 



