206 



E. Jergensen. 



13. Surirellese. 

 Campylodiscns Ehrb. 



C. decorns Breb. 

 C. deconts Breb. Diat. Cherb. p. 13, f. 2. Van Hedrck Synops. pi. 75, f. 3. 



Not unfrequent : Moskenstrommen r, Stamsund r, Ostnestiord r, 

 ( raukvsere r. 



Distribution (including the nearly related C. Ralfsii W. Sm.): 

 Frequent on the coasts of Europe. Greenland. Java. Pacific 

 Ocean. 



O. Ralfsii W. Sm. 



\V. Sm. Brit. Diat. I. p. 30, pi. 30. f. 257. A. Schm. Atlas pi. 14, tigs. 2—3. 



Differs from the preceding species in having a linear (not 

 lanceolate) pseudoraphe. Smaller in size. 

 Very rare: Stene r, Stamsund r. 



C. annularis Greg. 

 Greg. Diat. of Clyde p. 502, pi. XI, f. 53. A. Schmidt Atlas pi. 18, f. 7. 



Frequent: Raftsund r. Brettesnes— Skroven r, Gstnesfiord c, 

 Stene r. 



Distribution: Scotland. The Skagerak. Arctic regions. 



C. Tlmretii Breb. 

 Breb. Diat. Cherb. pi. 1, f. 3. Van Heurck Synops. p. 190, pi. 77, f. 1. 



Frequent: Moskenstrommen r, Stamsund +, Svolvser r-f-, 

 Kat'tsund r, Brettesnes— Skroven r, Gstnesfiord + c, Gaukvserfl -f-c, 

 Stene r -f-. 



Distribution: Frequent on the coasts of Europe. Arctic re- 

 gions. Indian Ocean. 



C. parriilus W. Sm. 

 \V. Sm. in Brit. Diat. I, p. 30, pi. 6, f. 5b'. Van Heurck Synops. p. 191, 



1>1. 77, f. 2. 



Is by some authors considered to be a form of C. Thuretii 

 Bkeb. (cf. De Toni Syll. p. 622) by others to belong to C. decorus 

 Brkb. (cf. Van Heukck Traite p. 37<i). 



Very rare: Stene r. 



Distribution: England. Belgium. 



C. eximius Greg. 

 Greg. Diat. of Clyde p. 503, pi. XI, f. 54. 



Very rare: Stene rr. Only a broken valve. 

 Distribution: Coasts of Western Europe. The Mediterranean. 

 Red Sea. Indian Ocean. 



Surirella Tukp. 



S. gemma Ehrb. 

 Ehrb. A1.1i. Berl. Akad. 1840, p. 76, pi. IV, f. 5. Van Heurck Synops. p. 187, 



pi. 74. figs. 1—3. 



Very rare: Gaukvsero rr. 



Distribution: Frequent on the coasts of Europe. Spitsbergen. 



*S. ovalis Bkeb. 

 Kutz. Bacill. p. 61, pi. 30, f. 64. Van Heurck Synops. p. 188. pi. 73. f. 3. 



In fresh and brackish water. 

 Very rare: Gaukvsero r. 



car. ovata (Kutz.) V. H. 

 VH. Synops. p. 188, pi. 73, figs. 6 — 7. Surirella ovata Kutz. 1. c. p. 62, pi. 7, 



tigs. 1—4. 



Very rare: Gaukvsero r. 

 Distribution: Common species. 



S. fastnosa Ehrb. 



Ehrb. Abh. Berl. Ak. 1841. p. 19. Van Hedrck Synops. p. 188, pi. 73. f. 18. 



Rather frequent: Svolvser -f-, Raftsund r, Gaukvsero r, 

 Stene r -f-. 



rar. lata ("W. Sm.) VH 

 Van Heurck Synops. p. 188, pi. 72, f. 17. Surirella I. W. Sm. Brit. Diat. I, 



p. 31, pi. 9, f. 61. 



Frequent: Moskenstrommen r-f-, Stamsund r, Svolvser r, 

 Raftsund r, Brettesnes — Skroven r, Gstnesfiord r, Gaukvaero r, 

 Stene r. 



Distribution: Frequent on the coasts of Europe. Gulf of 

 Mexico. 



14. Achnantheie Cl. 

 Arhiianthes Bory. 



A. longipes Ag. 



Ag. Syst. p. 1. Van Heurck Synops. p. 129. pi. 1";. figs. 13—16. 



Very rare: Svolvser r. 



Distribution: Frequent (on algae) mi the coasts of Europe. 

 The Canary Isles. 



A. breripes Ag. 



Ag. 1. c. Van Heurck Synops. p. 129, pi. 26. figs. 10—12. 



Rare: Stamsund r, Stene r, Gstnesfiord r. 

 Distribution: Frequent on the coasts of Europe. 



KiK'ot'eoiiois Cl. 



Valves ecostate. without marginal loculiferous rim. Both val- 

 ves- with narrow axial area, rather similar in structure. 



E. pseudomarginata (Greg.) Cl. 



Cl. Synops. Navic. Diat. II, p. 178. Cocconeis p. Greg. Diat. of Clyde p. 197, 



pi. IX, f. 27. G. major Greg. 1. c. f. 28. 



Rare: Stamsund r, Raftsund r, Gstnesfiord r, Stene r. 



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

 Mediterranean. Red Sea. Indian Ocean. Galapagos Islands. 

 Honduras. 



Hoti'i'oneis Cl. (includ. Discnneis Cl. 1. c. p. 180 and Actinoneis Cl. 



1. c. p. 185). 



Valves very dissimilar, without marginal loculiferous rim. Up- 

 per valve costate, sometimes only striate, then with broad axial area. 





