.1. luucilcntn tliii'.c. 



(jREll. DiiU. of Cly.lr 1.. :">HI. I'l. XU, I. (i:>. ('l.. I. cv 1.. I'.'l. 



Answers best to -4. rnimlciisix (iRv.u. 1. c. p. 'jl-i, pi. .\ll, I'. 71, 

 wliicli by CYevk 1. c. — probably riditly i.-< coii.Mdcicd ;i 



variety of .1. mm-ihuhi. Vv\\<U\W 4S >c l!i ii.. with rather narrow 

 eonnec-tinsz- /.one. 11 stria' on Ui ;i. 



Very rare: Stamsiuid, r. 



Distrihiition: Coasts of Sweden and Scothmd. The .Mc(htor- 

 ranean. Maea.ssar Straits. 



A. vunotiii I 'l.. 



\'ery rare: Stamsund, r. 



Similar to an Amplwni fmviis. witii distinctly punctate trans- 

 verse striæ. Valve SO x' 1.5 m its ends a little capitate-rostrate. 

 Striæ 7V2 on 10 [>.. 



Didrihiitioii: Bohusliin (Swed(Mi). Arctic regions. Indian 

 Ocean. 



A. costata W. Sm. 



W. Sm. Biit. Dial. I. p. '20, pi. 30, f. 2.i3. Greg. Diat. of Clyde p. 527, pi. XIV, 

 f. 99. .4. inflafa Guvs, in A. Schm. Atlas pi. 25, figs. 29-.30. 



Rare: Stamsund, r. 



Frustule 3i x 16 <>., coarse structure; 9—10 striæ on 10 ix; 

 many longitudinal division lines. Ends pi-otracted. 



Distribidion: Coasts of the North Sea. Mediterranean. Sumatra. 

 East coast of America. Galapagos Islands. 



A. terroris Ehrb. 



A. erehi Ehrb. Micvogeol. pi. 35 A, f. 2. A. cymhifera Grec;. Diat. of Clyde 



p. .52ti, pi. XIV, f. 97. A. Schm. Atlas pi. 26, f. 33: pi. 39, f. 18: pi. 25, 



figs. -17- 19, 33-34, 36. 



Not unfrequent : Stamsund + , the Østnesfiord r, Gaukværo r. 

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

 Meditci'i'anean. Macassar Straits, (xulf of Mexico. 



Svi 



A, ostrearia Bhéu. 



A. Hcii.MiUT Atlas pi. 2l>, f. 2:1. Van Hi 

 . I, f. 25 (rtir. t/fpirn ('i,. I. c. |i. 129). 



Rare: Stamsund, r; daukva-i'o, r. 



Dishihiitlon: Coasts of the North Sea. Finmark. Tiie .Medi- 

 terranean. Indian Ocean. Pacitic Ocean. 



Oxyainphora Ci,. 



p. 125 



Complex connecting zone. Valves acute with the I'aphe close 

 to the ventral margin. No dorsal lonsjitiuliual lines. Usually delic- 

 ate structure of transverse or slightly I'adiate striæ with puncta 

 arranged in undulating, longitudinal lines. \'entral side usually of 

 still finer structure than the dorsal side. Often a stauros. 



A. acuta Greg. 

 Greg. Diat. of Clyde p. 524, pi. 14, f. 93. A. Schji. Atlas pi. 2i), figs. 19—20. 



Not unfrequent: Stamsund r, the Ostnesfioi-d r. Raftsund r, 

 Gaukværø r. 



iJistiihiition: Coasts of tiie NortJi Sea. Arctic reu'ions. The 

 ilediterranean. China. Straits of Magellan. 



A. groenlandica Cl. 



Cl. 1. c. p. 128, pl. IV, f. 1. 



No stauros. 



var. 

 Median striæ 12 on 10 [>-, towards the ends of the valve some- 

 what closer. Puncta elongated, 10 on 10 |).. 

 Very rare: Stamsund, r. 

 Distrihiition of the main spedes: Davis' Strait. 



A. lævis Greg. 

 J14, pl. XII, figs. 74 a- 



A. Scii.M. Atlas, pl. 2() 



Rare: Stamsund, r +. 



Distrihiition: Coasts of the Nortli Sea. Fimnark. Balearic 

 Islands, .lava. 



var. lævissiina (Greo.) ('l. 



Cl. 1. r. p. i:iU. AiHijhora lævissima Greg. Diat. of Clyd»;, p. 51.-}, pl. XII. f. 72. 



A. Schm. Atlas pl. 26, figs. 3, 13—14. 



Rare: Stamsund r, Stene r. 



Distrihiition: Coasts of the North Sea. Finmark. Sea of Kara. 



e. Ainblyainpbora ('l. 1. c. p. l:iO. 



Connecting zone complex. Valves obtuse with tiie rapiie 

 diverging dorsally. No longitudinal lines. Fine puncta, arranged 

 in transverse striæ. Structure not finer on the ventral part of 

 the valve. 



A. obtnsa Gheg. 



Greg. Mici-. .loui-u. V. p. 72, pi. I, f. 34. A. Scum. Atlas pi. 40, figs. 4—7, 



11—13. 



Very rare: Stamsund, r. 



Distribution: Coasts of the North Sea. The Mediterranean. 

 Black Sea. Red Sea. Indian Ocean. China. East coast of 

 America. 



Greg. Diat. of 



A. spectabilis Greg. 

 p. 516, pi. XIII, figs. 80 a, c. A. Schm. Atlas pi. 40, 

 figs. 18-2.3. 



Not unfrequent: Stamsund +, Stene i-, Gaukva'ro r. 

 Distrihiitiun: Coa.sts of the North Sea. The Mediterranean. 

 Indian Ocean. Pacific Ocean. West Indies. Davis' Straits. 



t. Psammamphora Cl. 1. c-. ji. 132. 

 Connecting zone simple. Else as Amhhjimiiliora. 



A. ocfUata Donic. 



DONK. Micr. .Joui-n. 1861 (ii. s.) I, p. 11, pi, I, f. 11. V.vN Hecrck Synojis. p. 56. 



pi. I, f. 26 (var. ti/pica Cl. c. p. 133). 



Somewhat rare: Stamsund r, Svolvan- r. the Ostnesfiord r -{-, 

 Gaukværo +. 



Distrihiition: Coasts of the North Sea. Sweden. The Adriatic. 



g. Cyiuhaniphora Cl. 1. c. p. 134. 



Connecting zone simple. Valves of rather delicate structure. 

 No longitudinal lines. Raphe close to the ventral margin. 



A. atigusta Greg, r ('l. 

 Cl. 1. c. p. 135. Greg.'^ Diat. of Clyde p. 510. pi. XII, f. 66 (rai: tijiiirn Cl.). 



Rare: Stamsund, r. Hardly Gregory's species. 

 Distrihiition: Scotland. Arctic regions. East coast of North 

 America. West Indies. 



