M 



KONGL. SV. VKT. AKADRMIENS HANDLINGAR. HANI) 27. N:<) 3. 91 



I Valve large. L. 0,15 to 0,2 mm P. cardinalis Ehb. 



I — small L. (),os to 0,i2 mm 3. 



I Striae 7 to 7,5 in 0,oi mm P. ceatuarii Cl. 



I — 9 to 12 — — P. isostauron Grun. 



I Valve gibbous in the middle and at the ends f). 



I — not — — — — — — (5. 



Stri» 4,5 to 5 in 0,0 1 mm P. nohilin Ehb. 



— 7 in U,oi mm P. gentilis Donk. 



„ j StriiB parallel or slightly radiate 7. 



\ — strongly radiate P. distinguenda Cl. 



{ Valve with parallel 7Jiargins P. sfreptoraphr Cl. 



I — — convex — H. 



^ I Striae 4,5 to 5 in 0,oi mm P. fiejcuosn Cl. 



I — 6,5 (to 15) in 0,01 mm P. viridis Nitzsch. 



61. P. viridis Nitzsch (1817). — V. elliptic-linear, with parallel margins, attenuated to- 

 wards the rounded ends. L. (),i4 to 0,17; B. 0,02 to 0,o24 mm. Median line complex; terminal 

 fissures comma-shaped. Axial area linear, narrow, about ' , of the breadth of the valve, slightly 

 widened around the central nodule. Striae fi,.5 to 1 ,h in 0,oi mm. slightly divergent in the middle 

 and convergent at the ends, else almost parallel, crossed by a distinct band, about '/., of the length 

 of the strict>. — Bacillaria viridis Nitzsch PI. IV f. 1 to 3. Pinnnl. viridis Ehb. Inf. p. 182. Nav. 

 viridis KtJTZ Bac. p. 97 PI. XXX f. 12. A. S. Atl. XLII f. 11 to 14, 19, 21, 22, 23. V. H. Syn. 

 p. 73 PI. V f. 5. FiHHul. medioconstricta Rabh. A. Sachsens N:o 952 (1860). Nav. Gutvinskii Pant. 

 Ill PL XIV f. 217 (1893)? 



Fresh water: Sweden (Lapland to Skane)! Norway! Finland (Russian Lapland to Ladoga)! 

 Belgium (V. H.), (xermany (Franzenbad Dept.)! Hungary (Dubravica Dept. Grun.), Italy (Livorno, 

 Atl.), Australia (Talbot River, Victoria)! New Zealand! America (Illinois, California, Ecuador, 

 Brazil)! 



Var. intermedia Cl. (1891). — V. linear. L. 0,o75 to 0,ii; B. 0,oi4 to O.oi,^ mm. Area 

 about ' ,, of the breadth of the valve. Strise 8 to 9 in 0,o) mm. divergent in the middle, conver- 

 gent at the ends, crossed by a narrow band. - Nav. major A. S. A. Atl. XLII f. 9, 10. Finn, 

 virid. var. int. Cl. D. of Finl. p. n. Nav. viridis Pant. Ill PI. VII f. 119 (1893)? 



Fresh water: Sweden (Lapland, Smaland)! Finland! Scotland (Atl.), Congo (V. H. Coll.;! 

 Java! Australia (Blue Mountains)! 



Var. comnndata Grun. (1876). — V. linear. L. 0,o5 to 0,o9; B. 0,oi mm. Area narrow, 

 widened in the middle. Strict 10 to 12 in 0,oi mm. divergent in the middle, convergent at the 

 ends. Bands indistinct. — Pirinul. viridis W. Sm. XVIII f. 163 a'. Nav. commutata Grun. A. S. 

 Atl. XLV f. 35 to .37. Fiyin. Heu fieri Pedicino Ischia PI. II f. 17 (1867). Finn, sudctica Hilse 

 Rab. A. Eur. N:o 1023 (1861). Nav. decumana Pant. Ill PI. XXXV f. 499 (1893)? 



Fresh water: Sweden (Upsala, Rosslangen in Smaland)! Finland (Russian Lapland to La- 

 doga)! England Sm., Scotland (Lock Canmor Atl.), Germany (Harz, Atl.), France (Lac Gerardmer, 

 Vosges)! Tasmania! America (Canada, Waltham Mass., S:ta Rosa Calif., Sierra Nevada, Rio Purus 

 Brazil)! 



Similar to Finn. vir. var. commutata is Finn, oblongo-linearis Kostowsky (Materialy 1888 

 p. 23 PI. XVII f. 5) but this form has wider strife, about 6 in 0,oi mm. 



Var. leptofiomjyla (Ehb.?) Grun. (1876). — V. linear with parallel margins, or slightly 

 gibbous in the middle. Ends rounded. L. O.os; B. 0,oi mm. Area narrow, strongly dilated in 

 the middle to a rhomboid-orbicular space. Median line filiform. Terminal fissures semicircular. 

 Stri* 10 in 0,ui mm., divergent in the middle, convergent at the ends. — Nav. leptogongyla (jt'Rki^. 

 in A. S. Atl. XLV f. 26 to 28. Nav. Tahellaria Donk. B. D. p. 70 PI. XII f. 4? 



Slightly brackish water: Eger, Franzenbad foss.! 



Var. fallax Cl. — L. 0,04 5 to 0,09.5; B. 0,oo9 to 0,o 1 6 mm. Area very narrow. Strife 10 to 

 12 in 0,01 mm., almost parallel, frequently uni- or bilaterally interrupted. — Finniil. viridis (i W. Sm. 



