KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 26. N:0 2. 149 



Var. ampMlepta Ehb. (1843). — L. 0,o7 to 0,i; B. 0,oi5 to 0,02 mm. Striae and puncta 18 

 to 21 in 0,01 mm. — S. amph. Ehb. Am. I: 2 f. 9? M. G. PI. XIV f. 18? H^rib. D. d'Auvergne 

 p. 77 PI. Ill f. 18 (1893). S. gracilis W. Sm. B. D. XIX f. 186. S. lanceolata Grun. Verb. 1860 

 p. 563. S. horyana Pant. Ill PL V f . 78; 1893 {S. javanica?). 



Fresh water: Sweden! Finland! Holstein! England (Sm.), Greenland! Australia, Murray Eiver! 



Var. genuina Cl. — L. 0,i to O.is; B. 0,03 to 0,04 mm. Striae 14 to 17, puncta about 12 

 in 0,01 mm. — S. phoenicenteron W. Sm. B. D. PI. XIX f. 185. Grun. Verb. 1860 p. 563. V. H. 

 Syn. p. 67 PL IV f. 2. Pant. Ill PL VIII f. 134. S. Brunii Per. in Herib. d'Auvergne p. 76 

 PL III f. 22 (1893). 



Fresh water: Sweden! Finland! England! Belgium (V. H.), Switzerland! North America 

 (Canada, Calif.)! Brazil! Argentina! New Zealand! 



Var. Baileyi Ehb. (1843). — L. 0,i5 to 0,2; B. 0,o45 mm. Striae and puncta 12 to 14 in 

 0,01 mm. — S. Bail. Ehb. Am. p. 143. S. pteroidea Bail, (accord, to Ehb.) M. G. PL XIV f. 5. 



Fresh water: North America (Cherryfield etc. fossil)! 



19. S. (Pleurostauron) parvula Grun. (1878). — V. linear-lanceolate, with obtuse or slightly 

 rostrate ends. L. 0,02 to 0,025; B. 0,oo5 mm. Stauros broad, pervious. Striae 23 in 0,oi mm. 

 radiate. — Grdn. in Cl. M. D. N:o 139. 



Fresh water: Berlin! 



Var. prominula Grun. Ms. — Linear, with rostrate ends. L. 0,02 to 0,04; B. 0,oo4 to O.oos 

 mm. Striae 25 to 28 in 0,oi mm. 



Fresh or slightly brackish water: Greenland! Finmark, Tana Elf (Grun.), Gulf of Bothnia! 



Var. producta Grun. (1880). — V. linear lanceolate, with rostrate ends. L. 0,03 to 0,04; 

 B. 0.008 mm. Striae 18 to 20 in 0,oi mm. — Stauron. producta Grun. in V. H. Syn. PL IV f. 12. 



Fresh water: Sweden Skane! Holstein! (Grun.). 



As S. parvula Janisch has described, but not figured, a form from Angamos Guano (Charac. 

 d. Guano II p. 14), which cannot be identified, for which reason Grunow's name may be 

 retained. — S. parvula Grun. diifers from S. producta only by its smaller size and finer striae, 

 and they may be united. The var. producta is nearly akin to, and seems to graduate into 

 S. Legumen. 



20. S. (Pleurostauron) oblonga Grun. (1867). — V. linear, with broad, rounded ends. 

 L. 0,038 to 0,0.5; B. 0,0122 mm. Stauros linear, reaching to the margin. Striae transverse, 15 in 

 0,01 mm. — Grun. Nov. p. 20 PL I f. 15. 



Fresh water: Java, foss. (Grun.). 



I have not succeeded in finding this form in the edible earth from Java, and cannot say 

 anything about its afiinities. 



21. S. (Pleurostauron) obtusa Lagst. (1873). — V. linear-lanceolate, with broad, obtuse, 

 not rostrate ends. L. 0,06 to 0,07; B. 0,oi mm. Stauros broad, reaching to the margin, where it 

 becomes somewhat broader. Striae 19 to 21 in 0,oi mm. — Lagst. Spitsb. D. p. 36 PL I f. 11. 



Fresh water: Spitsbergen (Lagst.). 



A similar form from Australia (Blue Mountains) has slightly rostrate ends. Another similar 

 form, but with narrow, subacute ends, is described by Lewis (Proc. N. Sc. Philad. 1865 PL II 

 f. 14) as a variety of 8. Legumen. 



22. S. (Pleurostauron) Legumen Ehb. (1843). — V. elongated, biconstricted. Median infla- 

 tion not larger than the others. Ends rostrate. L. 0,o3 to 0,o3.5; B. 0,oo8 mm. Stauros reaching 

 nearly to the margin and not dilated outwards. Striae 27 in 0,oi mm., slightly radiate. Frustules 

 coherent in short bands. — Stauroptera Legumen Ehb. Am. p. 135 PL I: 2, f. 5 (fide Klitz.). Stauro- 

 neis Leg. Kutz. Bac. p. 107 PL XXIX f. 11. Greg. M. J. IV PL I f. 9. V. H. Syn. p. 69 

 PL IV f. 11. 



