KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 27. N:0 3. 131 



The forms comprised in this snbgenus agree in all respects, except in the complex nature 

 of the zone, with Psammanqjhora, for which reason it is impossible to decide whether detached 

 valves belong to one or other of the snbgenera. 



Ärtificial liey. 



_. I Stiise on the dorsal side furcate A. spectabilis Geeg. 



■ \ — — — not — 2. 



) Valve reniform A. obesa Cl. a. Grove. 



1 — linear 3. 



„ ) Valve abont 20 times longer tlian broart A. inflexa Bréb. 



' \ — 6 to 7 — — — — A. obtitsa Greg. 



1. A. inflexii Bréb. (1849). — Friistule linear, elongated, with truncate ends. Connecting 

 zone with close and iine divisions. V. arcuate, linear, with ronnded ends. L. 0,13; B. 0, 007 mm. 

 Median Iine raore approximate to the dorsal than to the ventral margin. Central nodule elongated. 

 No areas. Strite 20 in 0, 01 mm. parallel, convergent at the ends, where they are closer, very 

 finely punctate. — Ampliipleiira inflexa Bréb., Kutz Sp. Alg. p. 88. Ämphora infkxa H. L. Sm. 

 Lens 11 p. 78 Pl. Il f. 16 (1873). Okcdenia inflexa Eulenst. Ms. Cl. M. D. N:o 192 (1879). 

 V. H. T. N:o 1(37. 



Marine (pelagic): Firth of Tay! Adriatic! 



The fig. in The Lens does not give any idea of the appearance of this isolated and stränge 

 form. The complex natnre of the zone is very difficnlt to discover, and I am indebted to Prof. 

 Van Heurck for photographs of specimens, monnted in realgar, which shew it pretty well. 



2. A. obtusa GtREG. (1857). — Frnstule in oiitline elliptic-rectangular, somewhat more than 

 twice as long as broad. V. linear, obliquely ronnded. L. 0,065 to 0,26; B. 0,oi to 0,03.'> mm. 

 Median Iine not dilated to a staitros. StrisB 11 to 20 in 0, 01 mm. 



Forma iypica Cl. — L. of valve 0, 075 to 0,14; B. 0,03.5 to O, os mm. Dorsal and ventral 

 stricB 18 to 20 in 0,oi mm., composed of pnncta, 15 to 24 in 0, 01 mm. — ..4. ohtusa Greg. T. M. 

 S. V p. 72 Pl. I f. 34. A. S. Atl. XL f. 4 to 7, 11 to 13. Ampliiprora maxima Eab. Jan. 

 Hondnras D. p. 3 Pl. II f. 4 (1862). Toxonidea Uvis Witt J. Mus. Godeff. p. 70 Pl. VIII f. 9 

 (1873). Ämphora permac/na Pant. II p. 38 Pl. VI f. 113 (1889). 



Marine: North Sea! Mediterranean Sea! Adriatic! Black Sea! Red Sea! Seychelles! Mada- 

 gascar! Labiian! Celebes! China! Cape May! North Carolina! West Indies! Campeachy Bay! Mexico! 

 Porto Seguro! Fossil: Hnngary, Czekehaza! Oamarn (Stria; 17 to 18 in 0, 01 mm.). 



Forma minuta Cl. — ■ Frustule 0,o63 in length and in breadth 0, 03. B. of the valve 0, 03 

 mm. Strise 25 in 0, 01 mm.; pnncta abont 21 in 0, 01 mm. 



Marine: Macassar Straits! 



Var. oceanica Castr. (1886). — V. in L. 0,i3 to 0,26; in B. 0,028 to 0,o35 mm. Strise 15 

 in 0,01 mm., composed of pnncta, abont 15 in 0, 01 mm., which form undnlating, longitudinal rows. 

 — A. oceanica Castr. Challenger Exp. D. p. 20 Pl. XXVII f. 20. A. fallax Temp. et Brun D. 

 du Japon p. 14 Pl. VII f. 13 (1889). A. cyclojjs Ledd. Fortm. D. de Ceylon Pl. VIII f. 82 (1879)? 



Marine: Gulf of Naples (Deby Coll.)! Ceylon (Le Tourneur Coll.)! Sumatra (V. H. Coll.)! 

 China (l)eby Coll.)! Sydney (Castr.), Japan, fossil (Temp. a. Brun). 



Var. LunyacseJcii Pant. (1889). — L. 0,129; B. 0,028 mm. StritB 9 to 9,.ö in 0,oi mm. — 

 A. Lun. Pant. II p. 38; III Pl. XXXV f. 498. 



Marine: Hungary, fossil (Pant.). 



Var. transfuga Cl. — V. in L. 0,i8 and B. 0,023 mm. Strise 11 to 12 in 0,oi mm.; puncta 

 19 in 0,01 mm. — Ämphora obtiisa A. S. Atl. XL f. 16, 17? 



Marine: Madagascar! Macassar Straits! 



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