KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 26. N:0 2. 151 



Subdivision Schizostauron Grun. 



In the year 1867 Geunow founded (Hedwigia VI p. 28) this genus for some marine diatoms 

 from Honduras. The diagnosis is «Frustulia navicnlacea, valvis ovatis vel lanceolatis, nodulo cen- 

 trali transversim dilatato, lineari, utroque fine bifido (vel laciniato fimbriato)». 



Thej last characteristic modulo laciniato fimbriates refers to S. fimhriatum, which has since 

 been discovered to be the upper valve of Achnanthes danica. The other species named by Grunow 

 S. Lindigianum, S. ovatum and 8. Beichardhanum are entirely unknown to me. I have since 

 found three species of fresh vpater habitat, which agree with Stauroneis, but have a cloven stauros. 



28. S. Sagitta Cl. (1881). — V. lanceolate, with slightly triundulate margins and apiculate 

 ends having short diaphragms. L. 0,03 to 0,04; B 0,oo6 to 0,oi mm. Stauros bifid with parallel 

 branches. Striae slightly radiate, 21 in 0,oi mm. — Cl. N. E,. D. p. 15 PI. Ill f. 45. 



Slightly brackish water: Tana Elf in Finmark! Grulf of Bothnia! 



This little form has a great resemblance to S. Smithii, but has coarser striae and a bifid stauros. 



29. S. Crucicula G-run. (1881). — V. lanceolate, with rostrate, obtuse ends, having narrow 

 diaphragms. L. 0,03; B. 0,oo9 mm. Stauros bifid with divergent branches. Stride radiate, 25 in 

 0,01 mm. — Schizost. Crude. Grun. in Cl. N. R. D. p. 16 PI. Ill f. 44. 



Fresh water: Merrimac River! Rio Purus, Brazil! 



30. S. andicola Cl. (1881). — V. convex, linear with rounded ends. L. 0,o32 to 0,o36; 

 B. 0,007 to 0,008 mm. Terminal fissures in contrary directions. Stauros bifid, its branches divergent. 

 Striae almost transverse, 22 in 0,oi mm. — S. andic. Cl. Diat. fr. Groen. and Argentina PL XVI f. 8. 



Fresh water: Sierra de Velasco, Argentina! Cameroon! 



31. S. Lindigiana Grun. (1867). — V. broadly elliptical or suborbicular. L. 0,029; B. 0,o2i 

 mm. Median line complex. Central nodule transversely dilated, at the ends bifurcate; its branches 

 parallel to the margin. Striae 36 in 0,oi mm. parallel. — Schiz. Lindigianum Grun. Hedwigia 

 VI p. 28. S. Lindigii Grun. T. R. M. S. 1877 p. 181 PL CXCV f. 17. 



Marine: Honduras (Grun.). 



32. S. ovata Grun. (1867). — Valve, size and median line as in S. Lindigiana. Stauros 

 linear, with short, slightly divergent branches prolonged to the margins of the valve. Striae 26 

 in 0,01 mm, parallel. — Schiz. ovatum Grun. Hedwigia VI p. 28. 



Marine: Honduras (Grun.). 



33. S. Reichardtiana Grun. (1867). — V. broadly lanceolate, with subrostrate ends. L. 0,o2 6 

 to 0,036; B. 0,0 16 to 0,019 mm. Median line straight. Central nodule transversely dilated, bi- 

 furcate, with arcuate, divergent branches. Striae 12 in 0,oi mm. punctate, subradiate. — Schiz. 

 Beiehardtianum Grun. in Hedw. Vol. VI p. 28 (name only). Schiz. Beichardii Gbun. T. R. M. S. 

 1877 p. 181 PL CXCV f. 18. 



Marine: Adriatic (Grun.). 



Subdivisions Miorostigma and Libellus. 



34. N. Scopulorum Br^b. (1849). — V. linear, slender, often gibbous in the middle and at 

 the ends, with broad, rounded ends. L. 0,i to 0,26; B. 0,oo9 to 0,oi6 mm. Median line with 

 approximate central pores and distant terminal nodules. Terminal fissures indistinct. Axial area 

 indistinct; central very small. Striae 18 to 20 in 0,oi mm. radiate in the middle, convergent at 

 the ends, distinctly punctate, puncta about 19 in 0,oi mm., forming undulating longitudinal rows. 

 — Bb^b. in Klitz. Sp. Alg. p. 81. Grun. Verh. 1860 p. 547 PL III f. 6. Done. B. D. p. 73 PL XII 



