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



Var. obtnsa GtRun. Ms. — V. linear, with broad, rostrate ends. L. 0,o24; B. 0,oi)6 mm. 

 Strict 21 in 0,oi mm. closer toward.s the ends (24 in 0,oi mm.). 



Fresh water: Sandwich Islands, Mauna Kea (CI. M. D. N:o 141). 



Var.? nohilis ScnuM. (1867?). — V. lanceolate, rostrate. L. 0, ii; B. 0,023 mm. Stanros 

 narrowed towards the margins. Strise 16 in 0,oi mm., slightly radiate, composed of coarse, elongate 

 puncta, 15 in 0,oi mm., arranged in oblique, somewhat undulating rows. — S. nohilis Schum. P. 

 D. II Nachtr. p. 59 PI. II f. 60? 



Sliglitly brackish water: Klackeberga, Kalraar Ian, Sweden, fossil (Ancylus-epoch)! 



I am not convinced that this form is really the same as Schumann's, the puncta of which 

 are figured as arranged in obliquely decussating rows as in Pleurosigma Else the outline and the 

 size agree pretty well with Schumann's figure. 



B. Forms with capitate ends. 



Var. elougata Cl. — V. narrow linear-lanceolate. L. O,o.'5 5; B. Ojooa mm. Striifi 26 in 

 0,01 mm. — S. linearis var. in Cl. M. D. N:o 56. 



Fresh water: Germany! 



Var. amphicephala KtJTZ. (1844). — V. lanceolate. L. 0,04 to 0,08; B. 0,ooy to 0,oi5 mm. 

 StricB 21 to 22 in 0,oi mm. distinctly punctate. — S. amph. Kutz. Bac. p. 105 PI. XXX f. 25. 

 S. anceps W. Sm. B. D. I PI. XIX f. 190. V. H. Syn. p. 69 PI. IV f. 4, 5. 8. linearis Grun. 

 Verh. 1860 PI. VI f. 11. 



Fresh water: Spitsbergen! Sweden (VVesterbotten to Smaland)! Belgium (V. H.), England 

 (W. Sm.), Switzerland (Brun), Japan! Bengal! Greenland! Maine! California! Brazil! Ecuador! 



Var. recta Cl. — V. linear. L. 0,o45; B. 0,009 ram. Stria' 23 in 0,oi mm. 



Fresh water: Kuopio, Finland! 



Var. fossilis Cl. (1891). — V. lanceolate, with flattened, capitate ends. L. 0,o;»; B. 0,016 

 mm. Strife 23 in 0,oi mm. — Cl. D. of Finland p. 40 PL II f. 18. 



Fresh water: Sweden (Degernas in Westerbotten, fossil; Lake Rosslangen)! Finland (Savi- 

 taipale, foss.)! 



Var. argentina Cl. (1881). — V. lanceolate. L. 0,o65; B. 0,oi3 mm. Stauros not reaching 

 to the margins. Stria? 16 in 0,oi mm. — S. gracilis var. arg. Cl. D. fran Gronl. och Argentina 

 p. 12 PI. XVI f. 4. 



Fresh water: Sierra de Velasco, Argentina! 



16. S. Phyllodes Ehb. (1843). — V. lanceolate, with protracted, obtuse ends. L. 0,10.5; 

 B. 0,025 mm. Stauros narrower towards the margins. Strife 15 (middle) to 18 (ends) in 0,oi mm. 

 radiate throughout, punctate; puncta about 15 in 0,oi mm., arranged into irregularly undulating 

 rows. — Ehb. Am. PI. II: 1, f. 16 etc.? Icon. n. PL III f. 27. S. Sieholdii Ehb. M. G. PL 

 XXXIV: 8, f. 12? 



Fresh water: Demerara River! 



17. S. (lilatatii Ehb. (1843). — V. with parallel margins and rostrate, truncate ends. L. 

 0,06.5 to 0,068; B. 0,0 18 to 0,02 mm. Stauros broad, linear, reaching near to the margin. Strite 

 IS in 0,01 mm., radiate throughout, distinctly punctate, puncta 24 in 0, 01 mm., forming undulating, 

 longitudinal rows. ~ Ehb. Am. I: 2 f. 12. Cl. A. D. p. 4-s PL III f. {\2. 



Fresh water (larger lakes): Sweden, Malaren! Finland, Ladoga! Siberia, Mouth of Jenissey! 



18. S. Phoeiiicenteron Khb. (1843). — V. lanceolate, usually with slightly protracted, 

 obtuse ends. Ij. 0,07 to 0,2; B. 0,028 to 0,04 mm. Stauros linear. Striai radiate throughout 

 13 to 21 in 0,01 mm. distinctly punctate, puncta forming undulating, longitudinal lines. — 

 Ehb. Am. PL 11: .5 f. 1 etc. 



