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



Var. obtusa G-run. Ms. — V. linear, with broad, rostrate ends. L. 0,024; B. 0,oo6 mm. 

 StrisE 21 in 0,oi mm. closer towards the ends (24 in 0,oi mm.). 



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



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

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

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

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



Slightly brackish water: Klackeberga, Kalmar 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. elongata Cl. — V. narrow linear-lanceolate. L. 0,055; B. 0,oo9 mm. Striae 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,o4 to 0,08; B. 0,oo9 to O.ois mm. 

 Striae 21 to 22 in 0,oi mm. distinctly punctate. — S. amph. KUtz. Bac. p. 105 PL XXX f. 25. 

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

 Verb. 1860 PL VI f. 11. 



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

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



Var. recta Cl. — V. linear. L. 0,045; B. 0,oo9 mm. Strise 23 in 0,oi mm. 



Fresh water: Kuopio, Finland! 



Var. fossilis Cl. (1891). — V. lanceolate, with flattened, capitate ends. L. 0,09; B. 0,oi6 

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



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

 taipale, foss.)! 



Var. argentina Cl. (1881). — V. lanceolate. L. 0,065; B. 0,oi3 mm. Stauros not reaching 

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

 p. 12 PL XVI f. 4. 



Fresh water: Sierra de Velasco, Argentina! 



16. S. Phyllodes Ebb. (1843). — V. lanceolate, with protracted, obtuse ends. L. 0,105; 

 B. 0,02 5 mm. Stauros narrower towards the margins. Strifs 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. PL II: 1, f. 16 etc.? Icon. n. PL III f. 27. S. Sieboldii Ehb. M. G. PL 

 XXXIV: 8, f. 12? 



Fresh water: Demerara River! 



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

 0,065 to 0,068; B. 0,018 to 0,02 mm. Stauros broad, linear, reaching near to the margin. Striae 

 18 in 0,01 mm., radiate throughout, distinctly punctate, puncta 24inO,oi mm., forming undulating, 

 longitudinal rows. — Ehb. Am. I: 2 f. 12. Cl. A. D. p. 48 PL IH f. 62. 



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



18. S. Phoenicenteron Ehb. (1843). — V. lanceolate, usually with slightly protracted, 

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

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

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



