90 P. T. CLEVE, SYNOPSIS OP THE NAVICULOIO DIATOMS. 



Var. transversa A. S. (1876). — V. very slender. L. 0,i7 to 0,22; B. 0,02 mm. Median line 

 very broad and oblique. Striee 9 in 0,oi mm. — Nav. transversa A. S. Atl. XLIII f. 5 to 6. 

 Fresh water: Finland (Sodankylä)! America (Monticello) ! Australia (South Yarra)! 



58. P. Esox Ehb. (1843). — V. triiindulate, with obtuse ends. L. 0,o8 to 0,i45; B. 0,oi2 

 to 0,022 mm. Median line not complex, narrow. Terminal fissiires comma-like. Area linear, 

 narrow, less than V3 of the breadth of the valve. Striee 8 to 10 in 0,oi mm., divergent in the 

 middle, convergent at the ends, crossed by a narrow band. — Am. I: 2 f. 4? Schum. Pr. D. I 

 Pl. IX f. 36? Cl. Diat. of Finl. p. 24 Pl. I f. 3. Héeib. D. d'Auvergne p. 82 Pl. IV f. 4. 



Fresh water: Sweden (Älmten in Kalmar län)! Finland (Sodankylä)! Greenland! Puy de 

 Dome, fossil (Hérib.), America (Maine, Brun Coll.)! 



59. P. latevittata Cl. N. Sp. — V. linear, with broad, rounded ends. L. 0,i8; B. 0,o33 

 mm. Median line not complex, oblique; terminal fissures comma-shaped. Axial area broad, less 

 than ^/g of the breadth of the valve, widened in the middle. Strite 6 in 0, 01 mm., divergent 

 in the middle, convergent at the ends, crossed by a very broad band. — A. S. Atl. XLII f. 5. 



Fresh water: Puerto Monte, Chile, foss.! Ecuador! 

 , Var. Domingensis Cl. — V. slender, gibbous in the middle and at the ends. L. 0, 1 5 to 

 0,36; B. 0,022 to 0,04 mm. Strise 6 to 8 in 0,oi mm. — A. S. Atl. XLIII f. 3. Cl. Diatomiste 

 II Pl. VII f. 3. 



Fresh water: North America (Cherryfield, Atl.), West Indies, Jamaica and St. Vincent 

 (Grove Coll.)! San Domingo (Witt Coll.)! Ecuador! 



60. P. Dactylus Ehb. (1843). — V. subelliptic-linear, with rounded, obtuse ends. L. 0,17 

 to 0,32; B. 0,03 to 0,05 mm. Median line gently undulate, not complex. Central nodule large, 

 excentric; terminal fissures comma-shaped. Axial area moderately wide, about ^/j as broad as the 

 valve, irregularly linear-lanceolate. Striaä 4,5 to 5 in 0, 01 mm., crossed by a broad band. — Am. 

 p. 132 Pl. IV: 1 f. 3. P. Gigas Ehb. Am. p. 133, II: 3 f. 1. Navicula Dactylus A. S. Atl. XLII 

 f. 3, 4, 6. Nav. Dac. forma maxima V. H. Syn. Pl. V f. 1. Nav. Gigas A. S. Atl. XLII f. 1. 



Fresh water: Sweden (Lapland to Halland)! Norway! Finland! Scotland (Premnay Peat)! 

 France (Lac Gerardmer Vosges)! Amexica (common: most diatomaceous earths)! 



Var. horrida Hérib. a. Perag. (1893). — L. 0,i6; B. 0,025 mm. Area with irregularly 

 scattered spines. Striee 7 in 0,oi mm. — Nav. maj. var. Jiorr. Hérib. a. Pbrag. D. d'Auvergne 

 p. 83 Pl. IV f. 3. 



Fresh water: Puy de Dome (fossil). 



Var. Demerarce Cl. — Linear, with subcuneate ends. L. 0, 14; B. 0,o34 mm. Strise 5,5 in 

 0,01 mm. — A. S. Atl. XLIII f. 29. 



Fresh water: South America (Demerara River)! 



Var. Bariana A. S. (1876). — V. lanceolate, with obtuse ends. L. O, is to 0,2 1; B. 0,o4i 

 0,04 5 mm. Median line oblique, not complex, with comma-shaped terminal fissures. Axial area 

 broad, less than '/s of the breadth of the valve, widened in the middle. Strite 7 to 8 in 0,o2 mm., 

 divergent in the middle, convergent at the ends, crossed by a broad band. — Nav. Dariana A. S. 

 Atl. XLII f. 24, 25. 



Fresh water: America, Crane Pond! Schasta Co. Calif.! Neuse River (Atl.), Darien (Atl.). 



VIII. Oomplexse, 



.. i Central area a 

 \ — — n 



Ärtificial key. 



transverse fa.icia 2. 



not — — 4. 



