14 



p. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 



1. 

 2. 

 3. 



4. 

 5. 

 6. 



7. 

 8. 

 9. 



10. 



11. 

 12. 



Artificial Jcey. 



f Keel with decussating rows of puncta . . . 



\ — without — — — 



/ Keel with double rows of large marginal puncta . . 



\ — without — — — — 



( Keel not separate from the lower part of the valve 



\ ■ — separate — — — — 



J Valve siliceous ... . . 



\ — memhranaceous 



f Keel and valve separated by a row of puncta 



\ — — — — — junction-line . . . 



{Valve membranaceous . . . 

 — solid 



j Junction-line with several denticulations . . 



\ — — one or no — 



{Margin of the valve crenulated . . 

 — — not — 



I Strise of the keel obsolete . 



\ — — distinct 



{Striae on the keel wider than on the valve . 

 — — closer — — 

 — — and the valve aequldistant 

 {Keel strongly sigmoid 

 — slightly — . 



Striffi 6 in 0,oi mm. 



( Stria 6 

 I - 11 



to 12 



. A. gigantea Gbun. 



2. 



. A. Temperei Cl. 

 ... 3. 

 4. 

 ... .5. 



A. conspicua Geev, 

 .A. Duseni Cl. 

 A. margine punctata Cl. 



6. 



7. 



. . 8. 



A. ornata Bail. 



A. paludosa W. Sm. 



. A. crenulata Temp. 



9. 



A. Brebissoniana Gkbv. 



10. 



. . A. Kjellmanii Cl. 

 . A. kryophila Cl. 

 . . '. . 11. 



.... A. alata Ktiiz. 



12. 



A. Meneghiniana Grev. 

 A. lata Geev. 



1. A. Paludosa W. Sm. (1853). — Frustule membranaceous, in the zone- view deeply con- 

 stricted, with rounded to truncate ends. B. 0,03 to 0,o.5 mm. Junction-line sinuose (or not). 

 V. linear-lanceolate, with acute (or apiculate) ends. L. QIC's 5 to 0,i3 mm. Median line strongly 

 sigmoid. Striae 19 to 20 in 0,oi mm., some of them frequently coarser than the others. — W. Sm. 

 B. D. I. p. 44, PI. XXXI f. 269. V. H. Syn. p. 121, PI. XXII f. 10. 



Brackish water: North Sea (Sweden! England! Belgium!) Cape May! Barbados! 



Var. bahusiensis Cl. — Frustule strongly constricted. L. 0,08; B. 0,04 mm. Junction-line not 

 sinuose and not punctate. StricE 22 in 0,oi mm., those on the zone and the basal part of the valve 

 more marked. Striae of the keel faint, ending at the median line in very small puncta. 



Marine: Sweden, Fiskebackskil ! 



Var. africana GtRUN. (1879). — Frustule strongly constricted. L. 0,o.^ to 0,o6; B. 0,03 mm. 

 Junction-line not sinuose and not punctate. Striae 20 in 0,oi mm., those on the keel with coarse 

 puncta. — A. pal. v. afr. G-run. in Cl. M. D. N:o 196. 



Brackish water: South Africa! 



Var. subsalina Cl. — Frustule very thin, strongly constricted in the middle. L. 0,04: B. 

 0,03 mm. Junction-line with a large sinus. Striae 23 in 0,oi mm. — PL I f. 1. 



Brackish water: Artern, Saxony! 



Var. hyperborea Gkun. (1880). — Frustule slightly constricted in the middle. L. 0,065 to 0,07; 

 B. 0,035 to 0,036 mm. Junction-line slightly sinuose. Striae 27 to 28 in 0,oi mm. — A. pal. var.? 

 hyp. Grun. a. D. p. 62. PL V f. 86. 



Brackish water: Sea of Kara (Grun.). 



Forma minuta Grun. (1884). — L. 0,03 5 mm. — A. hyp. f. min. G-run. Franz Josephs L. D. 

 p. 54 (106), PL I f. 51. 



Marine: Franz Josephs Land (Grun.). 



