I*l4'lii'usi;;ilia AV. Sm. 



Jinplflirosiiiin:!. Sliiæ iii three direciions (tmusveise nuil oblii|Ue). 



P. nnhccula W. 



W. Sm. Brit. Diat. 1. p. tU. 



-'Ul. 



Cl. Svnops. Ni. 



var. snbrecta Cl. 



Diiit. I, p. ;!.">. Pleiiioniyiiia s. Cl., in ('i,, et CitiN. Aret. 

 DiMt. ].. 5:}. pl. a, f. 72. 



Very rare: Stam.sniiil, r. 254 n x 21 {)-; oblitiue striæ 18 

 on 10 n, angle more than 00", transvei-sc striæ indistinct. Kapiie 

 central, almost straisrht. Somewhat broader in the middle, with 

 obtuse ends. 



Distiihiitio)i (of the variety): Finmark. (Greenland. Sea of 

 Kara. Balearic Islands. 



P. elon^atnni W. Sm. 



AV. Sm. Brit. Diat. 1, \,\. 20, f. 199. Per.\gallo Monogv. Pleuros. pi. II. figs. 20—21. 



Very rare: The Ostnesfiord r. 



D'uftribiition : Coasts of the North Sea and Ireland. Baltic. 

 Arctic regions. The Mediterranean. Caspian Sea. North America, 

 east coast. Pacific Ocean. Indian Ocean. 



P. rigitlnm W. Sm. 



pi. 20, f. 198. Per.\g.\llo 



VI. figs. 4— ti. 



Very rare: Stamsund i', Gaukværo r. 



Dhtrihiition: Coasts of the North Sea. The Mediterranean. 

 Eed Sea. Indian Ocean. Pacific Ocean. West Indies. Straits of 

 Magellan. 



P. Norinanni Ralfs. 

 I. 919, F. affine Grcn. in Cl. et (iKr: 

 Van Hel-rck Synops. jjI. 18, f. 9. 



A ret. Diat. p. 



Fre([uent : Stam.sund r, Svolvær e, the Ostnesfiord -(- c. Stene c, 

 Gaukværø +• 



Dixtrihiidon: Coasts of the North Sea. The Mediterranean. 

 Spitsbergen. Davis' Strait. East coast of North America. Pacific 

 Ocean. The Red Sea. 



P. strigosum W. Sm. 



W. Sm. Brit. Diat. 1, p. 64, pi. 21, f. 203: pi. 23, f. 203. Perac. 1. c. pi. V, fig.s. 1—2. 



Very rare: Stamsund i-, Svolvær r. 



Distribution: Coasts of the North Sea. The Mediterranean. In- 

 dian Ocean. Africa. America. 



P. foruiosuni W. Sm. 



AV. Sm. Brit. Diat. I. p. 63. |,1. 20. f. 19."). Van Heirck Synoj.s. p. 116, 

 pi. 19, f. 4. 



Rare: Stamsund r, Stene r, Gaukværo r. 



Distribution: Coasts of the North Sea and ^^■estern Europe. 

 The Mediterranean. The Red Sea. Indian Ocean. Pacific Ocean. 

 West Indies. 



P. speciosimi W. Sm. 



AV. Sm. Brit. Diat. I, p. 63. pi. 20. f. 197. Perag. 1. c. pi. II, figs. 13—16. 



Verv I'are: Stene. r. 



Distribution: Coasts ol the North Sea. The Mediterranean. 

 Indian Ocean. Pacific Ocean. West Indies. 



(iyronigmii ( 1 1 as».). 



P. Httvmuitum (KiTz.) W. Sm. 

 \V. Sm. Brit. Diat. I. p. 68, pi. 22, f. 216. 



var. scalprutn (Jaili,. et Ti-rp. 

 TiHP. Jlem. <tii Mils. XV. pi. X, XI. f. 3. P. 

 Brit. Dial. I, p. 6t;, pi. 21. I'. 209. 



Very rare: The Ostncstioni. i'. 

 Distribution (of the vai'ietv): North Se: 



Ijiackish and marine. 



AA\ Sm. Brit. Diat. 



P. balticum (Ehkb.) AV. 8m. 



p. 66. pi. 22, f. 207. Xariada b. Kiirb. Abh. Berl 

 Ak. 18.30. p. 114. 



Very lare: Stamsund r, Svolvær r r. 



Distribution: Cosniopolifan in warm and temperate regions. 



KlioioosiKiiia Crin, Pf.k. 



R. arcticttm ('i.. 



Cl. Diat. Aret. Sea p. 18. pl. III. f. 16. Peragallo Mon. Pleur. pl. X, figs. 



16—17. Gyrosinttin a. Cl Syn^ips. Navic. Diat. I. p 119. 



Frequent: Stamsund r, the Ostnesfiord 1- c, Gaukværø c. 

 Distribution: Scotland. West coast of Norway, frequent. 

 Arctic regions. 



Seoliotropis Cl. 



S. latestriata (Bréb.) Cl. 



Cl. Syunps. Xavie. Diat. I, p. 72. Aiiij/hipyoia I. Bréb. in KiJTZ. Sp. Alg. p. 93. 



Scolioplewa I. Grux. in A'a.s Heibck Synops, pl. 17. f. 12. 



Very rare: Stamsund r, Stene r. 



Distribution: Coasts of the Nortii Sea and \\'estern Europe. 

 Caspian Sea. East coast of North America. West Indies. Cali- 

 fornia. 



Seolioplt'nra tumida (Bréb.) Babenu. 



Eabenh. Fl. Eur. Alg. p. 229. A' ax HErncK Synops, p. 112, pi. 17, figs. 11, 13. 



ynvicithi t. Bréb. in KiiTz. Sp. Alg. p. 77; Cl. 1. c. p. 1.5.5. 



Very rare: Oraukværo, r. 



Distribution: Coasts of the North Sea and Western Europe. 

 Franz .Josefs Laud. Black Sea. Cevlon. Sidney. 



P»<('niloani|>hi|>rora ('l. 



Cl. Synojjs. of Xavie. Diat. I. p. 71. 



According to Clevf, the foUomiig species has 2 chromato- 

 phores peculiar in sliapc and position. 



P. stauroptera (Bail.) Cl. 

 Cl. 1. c. Amphora stauroptera Bail. Smiths. Contrib. VII. p. 8, fige. 14—15. 

 Amphiprorn obtxtsa Greg. Diat. of Clyde p. .506. pi. Xlt, f. 60 ami f . 59 c („Amphi- 



prora IciAdoptera" Greg., non f. .59a, b.). A. Scum. Nords. Diat. pi. Ill, f. 1. 



Very rare: Stamsund r, tiie Ostnesfiord r. 

 Distribution: North Sea. Finmark. Sea of Kara. Nova 

 Scotia. Sidney. (Cl. 1. c). 



