208 



E. Jørgensen. 



Plenroneis Cl. 



p. 181. 



Marg-iaal loculiferous rim. Upper valve costate. Between the 

 costæ double I'ows of small pearls. 



p. costata (Greg.) Cl. 1. c. 



Cocconeis c. Greg, in Q. M. J. Ill, 185.5, p. 39, pi. 4, f. 10. Van Heurck 



Synop-*. pi. 30, figs. 11 — 12. 



Has a broad and well developed loculiferous rim. 

 Rare: Stamsund r, Østnesflord r, Stene r. 

 Distribution: Coasts of the North Sea. Arctic reg-ions. The 

 Mediterranean. Canada. Auckland. 



P. pinnata (Greg.) 



CocconeU p. Greg. Mior. .Jouni. VII, p. 79, pi. fi, f. 1. Van Heurck Syno])S. 



pi. 30, figs. 6—7. 



Lower valve: The raphe tine, straight, stretching' to the ends 

 of the valve, in the middle with clavate ends, somewhat separated 

 from each other. Axial area not visible, central one very small, 

 roundish. Stilæ very faint, not distinctly seen on my specimens. 



Tliere is a marginal rim with rudimentary loculi which are 

 less tiian half developed, but very well visible, 4 on 10 [j.. A 

 distinct hyaline border. This species seems on the whole to be 

 closely related to Phuroneis costata though undoubtedly a separate 

 species. 



P. britanniea (Næg.) Ci>. 



Cl. 1. c. p. 181. Cocconeis b. KuTZ. Sp. Alg. p. 890. Van Heurck Synops. 



pl. 30, figs. 1—2. 



Very rare : Stamsund r r. 



Distribution: England. The Mediterranean. The Barbadoes. 



RlioieoNplioiiia Grun. 



JR. ciirvata (Ivutz.) Grun. 



(iRUN. Am. Novara p. 8. Gomphonema c. KiJTZ. 1883. Gomphonema minutis- 



sima Ehrr. Mikrogeologie pi. 35 A, XII, f. 5, non G. minutissima Geev. (earlier 



name, = G. exiguum Kutz.). 



In fresh or brackish water. A coarser form (var. nmrina 

 Van Heurck Synops, pl. 26, f. -1) marine. 

 Very rare: Svolvær r, Ostnesfiord r. 

 Distribution: Cosmopolitan in fresh and brackish water. 



15. G<>iu])h(meineæ. 



4iioiii|»iioii(>iiia Ag. 



(i. constrictiini Emm. 

 Eiirr. Ahh. Brrl. Ak. 1H30. Van Heurck Synojjs. p. 123, pi. 23, 



Very rare: Svolvær r. 



Distribution: Common fresh water species. 



O. cxitiiiiiin KiiTz. 

 Kutz. ISacill. p. 84, pi. 30, f. 58. 



var. pachyclada (Bréb.) VH. Synops, pl. 25, fig.s. 31—32. 

 Gomphonema p. Bred. Consid. p. 21. 



Very rare: Stene rr. 



Distribution: West coast of France. Arctic regions. 



G. kamtschaticum Grun. 

 Grun. Casp. Sea Alg. p. 12. Van Heurck Synops. 25, f. 29. 



Very rare: Svolvær, r r. Valve 45 x 8 ]j-, narrow, clavate, 

 with rounded bfoader end. Axial ai-ea narrow, dilated to an oblong 

 central area. Striæ little radiating, coarser outside the central 

 area, about 15 on 10 |x, in the middle only 11. 



Distribution: (Marine). Arctic America and Asia. Iceland. 



16. Navictileæ. 



Anricnla complexa (Greg.) De T. 



De Toni Syll. p. 347. AnipJiipora complexa Greg. Diat. of Clyde p. 508, 



pi. XII, f. 62, Van Heurck Tiaité d. Diat. p. 267, pi. 29, f. 807. 



Probably derived from the plankton. 

 Very rare: Østnesflord r. 

 Distribution: Cf. above p. 108. 



Tropidoiieis Ci 



T. maxima (Greg.) Cl. 



Cl. Synops. Navic. Diat. I, p. 26. Amphiprora m. Gbeo. Diat. of Clyde p. 507 



pi. XII, f. 61. Van Heurck Synops, p. 120, pi. 22, figs. 4—5. 



Somewhat rare: Stamsund r, Svolvær r, the Østnesflord r, 

 Stene r -f, Gaukværø i'. 



Distribution: Coasts of the North Sea and Ireland. The 

 Mediterranean. Finmark (var. dubiu Cl. et Grun.). Indian 

 Øcean. 



T. lepidoptera (Greg.) Cl. 



Cl. 1. f. p. 25. Amphiprora I. Greg. Diat. of Clyde p. 505, pi. XII, f. 59 a, b 



(non c). Van Heurck Synops, p. 120, pi. 22, figs. 2—3. 



Not unfrequent: Stamsund -f, Svolvær r, the Østnesflord r, 

 Stene v -\-, Gaukværø r. 



Distribution: Coasts of the North Sea and Western Europe. 

 Finmark. The Mediterranean. West Indies. Indian Øcean. Pacific 

 Øcean. 



I>oiikiiiBa Hales. 



D. recta (Donk.) Grun. 



Grun. in Van Heurck Synops, p. 119, pi. 17, f. 9. Pleurosigma r. Donk. 



Micr. Join-n. VI, p. 23, pi. 3, f. 6. Gi/rosiijma r. Cl. Synops. Navic Diat. I, 



p. 119. 



Very rai'e: Stamsund, r. 



Distribution: Coasts of the North Sea and Western Europe. 

 The Mediterranean. J'^lorida. Pacific Øcean. Indian Øcean. 



Z). carinata (Donk.) Rales. 

 Ralfs in Pritcii. Inf. p. 921. Van Heiirck Traité d. Dia 

 Plcurosiyma c. Donk. Micr, .lonni. VI, ji. 23. pi. ,'i, f. 



). 248, pi. ;35, f. 912. 

 Cl. 1. c. p. 44. 



Rare: The Østnesfiord r, Stene i', Gaukværø r. 

 Distribution: Coasts of the North Sea and Ireland. Sea 

 Kara. Davis' Strait. Balearic Islands. 



