92 1*. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. " 



Br. D. XVllI f. 163 ^. New. scmicruciata A. S. Atl. XLIV f. 43? XLIll f. 24. Nav. viridis 

 var. commutata V. H. S. p. 73 PI. V f. 6.- A. S. Atl. XLV f. 10, 11. 



Fi'esh water: Sweden (Lapland to Smaland)! Belginm (V. H.), Germany (Harz Atl.. Eis- 

 leben Atl.), Australia (Waltham Mass., Monticello, Sierra Famatina Argent., Rio Purus Brazil)! 



According to Van Heurck's Syn. the valves of the same frnstule are dissimilar, the stria? 

 being in one uninterrupted and in the other unilaterally interrupted. This variety, confounded 

 witli the preceding, is distinguished by its almost parallel stria'. 



Var. semicruciata Grun. (1882). — V. large. Stria?, unilaterally interrupted. — Nav. viridis 

 var. semicruciata Grun. Foss. D. Oster. Ung. p. 143. 



Fresh water: Hungary, foss. (Grun.). 



Var. rupestris Hantzsch (1861). — L. 0.04 to 0,o65; B. 0,uo7 to 0,oi2 mm. Area very 

 narrow. Stria? 13 to 15 in O.oi mm. divergent in the middle, convergent at the ends. — Pinnul. 

 rap. Hantzsch Rab. Alg. E. N:o 1203. Nav. rup. A. S.^ Atl. XLV f. 38 to 44. 



Fresh water: Sweden (Top of the mountain Areskutan ! Vernamo, foss., Atl.), Norway! 

 Finland! Denmark (Ringkiobing, Atl.), Holstein! Iceland! Scotland (Braemar, Edinburgh, Loch 

 Canmor, Atl.), Saxony! America (Cherry field)! Martinique! 



Var. dispar Schum. (1862). — Area unilateral. L. 0,o.t to 0,o6 mm. Strife 7 in 0,(»i mm. 

 — Nav. dis. Schum. P. D. 1 Nachtr. p. 189 f. 50. 



Fresh water: Konigsberg, foss. (Schum.). 



(y2. P. (Iisting:uen(la Cl. (1891). — V. linear to elliptic-linear, with rounded ends. L. 0,io 

 to 0,18; B. 0,02 to 0,026 mm. Median line distinctly complex; central nodule large, excentric; 

 terminal fissures comma-like. Axial area broad, about V^ of the breadth of the valve, irregularly 

 linear-lanceolate, unilaterally widened in the middle. Striae 7 in 0,oi mm., strongly divergent in 

 the middle and convergent at the ends, crossed by indistinct bands. — Nav. viridis Kutz Bac. IV 

 f. 18. Pinnul. viridis W. Sm. f. 163 a. Pinyiid. viridis var. distinyuenda Cl. D. of Finl. p. 22 

 PL I f. 1. Nav. Hyrflii Pant. Ill PI. XVII f. 257 (1893)? Nav. viridis var. fossilis Pant. Ill 

 PI. XII f. 193 (1893). Nav. paripinnafa Pant. Ill PI. XVIII f. 263 (1893)? 



Brackish or fresh water: Sweden (Carlshamn and Sodertelge Depts.)! Finland! Hungary 

 (Bory Dept.)! Kamtschatka! Africa (Congo V. H. Coll.)! Australia (South Yarra, Tasmania)! New 

 Zealand! America (Houghton foss., Michigan Shasta Co. and S:ta Rosa Cal., Washington Territory, 

 Sierra Famatina, Argent.)! 



63. P. gentilis Donk. (1873). — V. linear, with parallel margins and broadly rounded ends. 

 L. 0,14 to 0,25; B. 0,022 to 0,036 mm. Median line slightly complex, with somewhat approximate 

 central pores and comma-shaped terminal fissures. Axial area narrow, less than '/3 of the breadth 

 of the valve. Strite 7 in 0,oi ram., divergent in the middle, convergent at the ends, crossed by a 

 moderately broad, not very distinct, band. — Nav. gentilis Donk. Br. D. p. 69 PI. XII f. 1. A. S. 

 Atl. XLII f. 2. 



Fresh water: Sweden (Lapland to Upland)! Finland! England (Donk., Atl.), Schlesien 

 (Gronowitz foss.)! United States (Salem Mass., Waltham Mass.)! 



64. P. iiobilis EiiB. (1840). V. linear, slightly gibbous in the middle and at the broadly 

 rounded ends. L. 0,2.^ to 0,35; B. 0,o34 to 0,o.t mm. Median line complex, with somewhat approxi- 

 mate centra] pores and comma-shaped terminal fissures. Axial area linear, less than '/j of the 

 breadth of the valve, slightly widened around the central nodule. Stria' 4,.', to 5 in 0,oi mm. 

 divergent in the middle, convergent at the ends, crossed by a distinct band, ^,3 as broad as the 

 length of the striffi. — Ber. 1840 p. 214. W. Sm. Br. D. XVIII f. 161. P. mesogongyla Ehb. p. p. 

 M. G. VI: I f 5. Nav. nobilis KtJTz Bac. p. 98 PI IV f. 24. Donk. Br. D. p. 68 PI. XI f. 1. 

 V. H. Syn. p. 73 PI. V f. 2. A. S. Atl. XLlIl f. 1. 



