92 . P. T. CLEVE, SYNOPSIS OE THE NAVICULOID DIATOMS. 



Br. D. XVIII f. 163 (t Nav. semicrueiata A. S. Atl. XLIV f. 43? XLIII f. 24. Nav. viridis 

 var. commutata V. H. S. p. 73 Pl. V f. 6. A. S. Atl. XL V f. 10, 11. 



Fresh water: Sweden (Lapland to Småland)! Belgium (V. H.), Germany (Harz Atl.. Eis- 

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



According to Van Heukck's Syn. the valves of the same frustule are dissimilar, the strife 

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

 with the preceding, is distinguished by its almost jDarallel strise. 



Var. semicrueiata Grun. (1882). — V. large. Strite imilaterally interrupted. — Nav. viridis 

 var. semicrueiata Grun. Foss. D. Öster. Ung. p. 143. 



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



Var. rupestris Hantzsch (1861). — L. 0,o4 to 0,o65; B. 0,oo7 to 0,oi2 mm. Area very 

 narrow. Striee 13 to 15 in 0,oi mm. divergent in the middle, convergent at the ends. — Pinmil. 

 rup. 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 (Ringkiöbing, Atl.), Holstein! Iceland! Scotland (Braemar, Edinburgh, Loch 

 Canmor, Atl.), Saxony! America (Cherryfield) ! Martiniqiie! 



Var. dispar Schum. (1862). — Area unilateral. L. 0,o5 to O, os mm. Strife 7 in 0,oi mm. 

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



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



62. P. distinguenda 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'3 of the breadth of the valve, irregularly 

 linear-lanceolate, unilaterally widened in the middle. Strise 7 in 0,oi mm., strongiy divergent in 

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

 f. 18. Finnul. viridis W. Sm. f. 163 a. Pinmil. viridis var. distinguenäa Cl. D. of Finl. p. 22 

 Pl. I f. 1. Nav. Hyrtlii Pant. III Pl. XVII f. 257 (1893)? Nav. viridis var. fossilis Pant. III 

 Pl. XII f. 193 (1893). Nav. paripinnata Pant. III Pl. XVIII f. 263 (1893)? 



Brackish or fresh water: Sweden (Carlshamn and Södertelge Depts.)! Finland! Hurigary 

 (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 Vg of the breadth 

 of the valve. Strite 7 in 0, 01 ram., divergent in the middle, convergent at the ends, crossed by a 

 raoderately broad, not very distinct, band. — Nav. gentilis Donk. Br. I), p. 69 Pl. XII f. 1. A. S. 

 Atl. XLII f. 2. 



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

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



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

 rounded ends. L. 0, 2.') to 0,35; B. 0, 034 to 0,o.'j rara. Median line complex, with somewhat approxi- 

 mate central pores and comma-shaped terminal fissures. Axial area linear, less than V3 of the 

 breadth of the valve, slightly widened around the central nodale. Strire 4,5 to 5 in 0,01 mm. 

 divergent in the middle, tionvergent at tiie ends, crossed by a distinct band, '/_., as broad as the 

 leiigth of the striiu. — Ber. 1840 p. 211. W. Sm. Br. D. XVIII f. 161. P. me.sogonffyla Ehb. p. p. 

 M. G. VI: 1 f 5. Nav. noUlis KtJTz Hac. p. 98 Pl IV f. 24. Donk. Br. D. p. 68 Pl. XI f. 1. 

 V. H. Syn. p. 73 Pl. V f. 2. A. S. Atl. XLIII f. 1. 



