68 r. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 



Artificial Icey. 



I Valve elongated, 8 to (i times longer than broad 2. 



\ — broad, 2 to .'5 ' 7. 



Margins parallel •.-.... o. 



— convex 4. 



. — undulating 5. 



f Ends rounded N. hisulcatnm Lagst. 



3. •] — cuneate j.V. amphigomphns Ehb. 



I — rostrate N. affiyic Ehb. 



f Ends rounded X. Iridis Ehb. 



i- I — subrostratc '. '. N. Iridis var. 



[ — rostrate-capitate X. productum W. Sm. 



j Ends broad, rounded N. affine var. 



( — cuneate 6. 



Strife slightly oblique N- Hitchcockii Ehb. 



strongly N. oblique- striatum A. S. 



L. 0,03 to 0,04 mm N. diihium Ehb. 



L. 0,06 mm X. dilatatnm Ehb. 



L. 0,07 to 0,1 mm X. citrcnm A. S. 



L. 0,1 G mm X. tiimescens Geun. 



5. 



( Strif 



1. N. bisulcatuiu Lagst. (1873). — V. linear, with rounded ends. L. 0,04 to 0,o7; B. 0,008 

 to 0,oo'.» mm. Stria; 28 to 30 in 0,oi mm., distinctly punctate. • — Nuoic. hisidcata Lagst. Spitsb. 

 D. p. 31 PI. I f. 8. A. S. Atl. XLIX f. 15, 17. N. scita W. Sm. Ann. Mag. n. hist. XIX p. 10, 

 PI. II f. 4 (1857)? 



Fresh water (alpine regions): Greenland! Spitsbergen! Beeren Eiland (Lagst.)! Dovre, Nor- 

 way! Sweden (Areskntan, Westerbotten etc.)! Finland! Lac Gerardmer (Vosges)! Argentina! 



2. N. affine Ehb. (1843). - V. linear, with rostrate ends. 



Var. loHgiccpa Greg. (1856). — V. small, l'rei|uently with undulating margins. Ends bruad, 

 rostrate or rostrate-capitate. L. 0,03; B. 0,oo5 mm. Strite very fine. — Nav. longiceps Greg. M. 

 J. IV PL I f. 27. 



Fresh water: Greenland! Scotland (Greg.)! 



Var. nnduluta Grun. (1860). — V. .slightly triundulate, with broad, rounded ends. L. 0,07; 

 B. 0,0 i;i mm. Stride 24 in 0,oi ram. — ]Sac. aff'. vur. tindiilala Grun. Verh. 1860 p. 544. PI. V 

 f. 6. V. H. Syn. PI. XIII f. 6. 



Fresh water: Sweden (CI. M. L. N:o 103), Belgium (V. H.). 



Var. amphirhynchus Ehb. (1843). — V. with protracted, rostrate-capitate ends. 



Forma minor: L. 0,04 to 0,05; B. 0,oo8 to 0,oi3 mm. Strise 25 to 27 in 0,oi mm. 



Fresh water: Sweden (Upsala)! Astralia (Blue Mountains)! 



Forma major: L. 0,09; B. 0,oi mm. Strire about 16 in 0,oi mm. — Nav. a f finis Ehb. Am. 

 Ill: 1, f. 10 etc. Nav. am,phir1ujnclms W. Sm. B. D. XVI f. 142. Donk. B. 1). p. 34 PI. V f. 0. 

 A. S. Atl. XLIX f. 27 to 30. Nav. aff. var. amphirh. Grun. Verh. 1860 PI. Vf. 5, 11. Nav. Ir(dis 

 var. uniphirh. V. H. Syn. PI. XIII f. 5. 



Fresh water: Spitsbergen (Lagst.), Beeren Eiland (Lagst.), Scotland! England! Belgium 

 (V. H.)! Sweden! Finland! New Zealand! 



Var. genuina Cl. — V. with rostrate, less protracted ends. 



Forma minor: L. 0,04.5 to 0,06.5; B. 0,oo8 to 0,oi3 mm. Strife 22 to 29 in 0,oi mm. — 

 Nav. af finis Ehb. Am. 11: 2. f. 7; 4 f. 4. Kurz. Bac. XXVIII f. 65. Nav. a f finis var. A. S. Atl. 

 XLIX fig. 20 to 23. Nav. hisulcata var. turgidula Lagst. Spitsb. D. p. 32 PL I f. 9. 



Fresh water: Spitsbergen (Lagst.), Lappland! Finland (Tulomian Lappmark)! Italy (Atl.)! 

 Australia (Blue Mountains and Tasmania)! 



