KONGL. SV. VET. AKADEMIENS IIANDLINOAH. HAM) 26. N:() 2. 151 



Subdivision Schizostauron (Ikun. 



In tliP year 18fi7 Grunow founded (Hedwigia VI p. 28) tliis genus for some marine diatoms 

 from Honduras. The diagnosis is &Frustulia naviculacea, valvis ovatis vel lanceolatis, nodnlo cen- 

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



Thej last characteristic nodulo laciniato fimbriato» refers to S. finihriafum, which has since 

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

 S. Lindigianmn, S. ovation and S. lieichardhanum are entirely unknown to me. I have since 

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



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

 ends having short diaphragms. L. 0,03 to 0,o4; B 0,oo6 to 0,oi mm. Stauros bifid with parallel 

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



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



This little form has a great resemblance to S. SniHhii, but has coarser strite and a bifid staviros. 



29. S. Cruciciila Grun. (1881). — V. lanceolate, with rostrate, obtuse ends, having narrow 

 diaphragms. L. 0,o3; B. 0,oo9 mm. Stauros bifid with divergent branches. Striae radiate, 25 in 

 0,0 1 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. 

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



Fresh water: Sierra de Velasco, Argentina! Cameroon! 



31. S. Lindi^iana Grun. (1867). — V. broadly elliptical or suborbicular. L. 0,029; B. 0,021 

 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. — Scliiz. Lindigiamim Grun. Hedwigia 

 VI p. 28. S. Lindtgii Grun. T. R. M. S. 1877 p. 181 PI. 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. Stria? 26 

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



Marine: Honduras (Grun.). 



33. S. Reichardtiana Grun. (1867). — V. broadly lanceolate, with subro.strate ends. L. 0,02 6 

 to 0,03 6; B. 0,0 16 to 0,0 19 mm. Median line straight. Central nodule transversely dilated, bi- 

 furcate, with arcuate, divergent branches. Strife 12 in 0,oi ram. punctate, subradiate. — Schiz. 

 Reichardtianmn Grun. in Hedw. Vol. VI p. 28 (name only). Sehiz. lieichardii Grun. T. R. M. S. 

 1877 p. 181 PI. CXCV f. 18. 



Marine: Adriatic (Grun.). 



Subdivisions Microstigma and Libellus. 



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

 the ends, with broad, rounded ends. L. 0,i to 0,2 6; B. 0,oo9 to 0,oig mm. Median line with 

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

 indistinct; central very small. Strife 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. 

 — Br^b. in Kutz. Sp. Alg. p. 81. Grun. Verb. 1860 p. 547 PI. Ill f. 6. Donk. B. D. p. 73 PI. XII 



