KONGL. SV. VET. AKADEMIENS HANDLINOAR. BAND 26. N:i) 2. 151 



Subdivision Schizostauron Ghun. 



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

 from Hondtiras. The diagnosis is «Frnstulia naviculacea, valvis ovatis vel lanceolatis, nodulo cen- 

 trali transversim dilatato, lineari, ntroqne fine bilido (vel laciniato fimbriato);'. 



TheJ last cliaracteristic vnodulo laciniato fimbriato» refers to S. fimhriatum, wliich bas since 

 been discovered to be the uioper valve of Achnanthes äanica. The other species named by Grunow 

 (S. Lindigianmn, S. orafum and S. EeicJiardtianum are entirely nnknown to me. I have since 

 found three .species of fresh water habitat, which agree with Stanroneis, bnt have a cloven stanros. 



28. S. Sagitta Cl. (1881). — V. lanceolate, with slightly trinndnlate 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. StricE slightly radiate, 21 in 0,oi mm. — Cl. N. R. D. p. 15 Pl. III f. 45. 



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



This little form bas a gTeat resemblance to S. Smilliii, but bas coarser strite and a bifid stanros. 



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

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

 0,01 mm. — Schizost. Criicic. Grun. in Cl. N. R. D. p. 16 Pl. III f. 44. 



Presh water: Merrimac River! Rio Purns, Brazil! 



30. S. andicola Cl. (1881). — Y. convex, linear with ronnded ends. L. 0,o3 2 to 0,o36; 

 B. 0,007 to 0,008 mm. Terminal fis.snres in contrary directions. Stanros bifid, its branches divergent. 

 Strise 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 suborbicnlar. L. 0,029; B. 0,021 

 mm. Median line com2)lex. Central nodnle transverselj- dilated, at the ends bifurcate; its branches 

 parallel to the margin. Strite 36 in 0,oi ram. parallel. — Schiz. Lindiyianum Grun. Hedwigia 

 VI p. 28. S. Lindicjii Grun. T. R. M. S. 1877 p. 181 Pl. CXCV f. 17. 



Marine: Honduras (Grnn.). 



32. S. ovata Grun. (1867). — Valve, size and median line as in 5'. Lindigiana. Stanros 

 linear, witli short. slightly divergent branches prolonged to the margins of the valve. Strite 26 

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



Marine: Honduras (Grun.). 



33. S. Rcicliardtiana Grun. (1867). — V. broadly lanceolate. with snbrcstrate ends. L. 0,02 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. Striee 12 in 0,oi mm. punctate, subradiate. — Schiz. 

 Eeichardtianum Grun. in Hedw. Vol. VI p. 28 (name only). Schiz. Bcichardii Grun. T. R. M. S. 

 1877 p. 181 Pl. CXCV f. 18. 



Marine: Adriatic (Grun.). 



Subdivisions Microstigma and Libellus. 



34. N. Scoptilorum Bréb. (1849). — V. linear, slender, often gibbous in the niiddle and at 

 the ends, with broad, ronnded 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. Striee 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. 

 — Bréb. in Kiltz. Sp. Alg. p. 81. Grun. Verh. 1860 p. 547 Pl. III f. 6. Donk. B. D. p. 73 Pl. XII 



