88 p. T. OLEVE, SYNOPSIS OF .THE NAVICULOID DIATOMS. ' 



0,0 1 mm. parallel, convergent at the ends. — NaiK mndrsia (tRUN. Foss. 1). Oster. Ung. p. 143 

 PI. XXX f. 39. 



Fresh water: Hungary, foss. Grim., Ecuador (Riobamba)! 



VII. Majores. 

 Artificial keif. 



{ 



^ . Terminal fissures in contrary directions 2. 



— — the same — 3. 



Ends broad, rounded P. Flamma A. S. 



snbcapitate P. Flammnla A. S. 



. J StriiB parallel or slightly radiate 4. 



\ — radiate f). 



I Area broad P. mncilenta Ehb. 



narrow P. Heccrnenda A. S. 



Band across the striae broad (>, 



— — narrow or indistinct 7. 



j Elli])tic-lanceolate P. Dactylns Ehb. 



H 



\ Linear with broad, ronnded ends P. lateriffafa ('l. 



j Are£ 



_ , Area very narrow 8 



moderately broad 9. 



slightly radiate P. conspicua A 



strongly — P. oregonica Cl. 



{ 



jj j Striae slightly radiate P. conspicua A. S. 



„ J Valve with uudulate margins P. Esox Ehb. 



Margins not undulate 10. 



) Ends triangular P. trigonocephala Cl. 



) — rounded or subcuneate P. major KliTZ. 



50. p. macilenta (Ehb. 1843) Cl. — V. linear, with broadly obtuse ends. L. 0,ii to 0,i.^, ; 

 B. 0,0 17 to 0,02 mm. Median line broad, oblique, not complex; its central pores approximate and 

 the terminal fissures comma-like. Axial area wide, less than a third of the breadth of the valve, 

 linear, scarcely widened in the middle. Stripe parallel, 8 to 9 in 0,oi mm. crossed by a narrow 

 band. — EiiB.'Am. 21 f. 23? M. G. T f. 7; I: .3 f. 13. Cl. Diat. of Finland p. 24 PI T f. 27. 



Fresh water: Sweden (Lake Wenern, Lake Ros.s]angen in Kalmar Ian)! Finland (Nyland, 

 Pudasjarvi)! Hungary (Bory, fos.sil)! America (Pine spring. Hermico Co, Va, Deby Coll.)! 



51. P. secernenda A. S. (1876). — V. linear, with broadly rounded snbcapitate ends and 

 slightly gibbous micklle. L. 0,1?; B. 0,o2i mm. Median line oblique with approximate central 

 pores. Axial area narrow, not dilated around the central nodule. Stri;e 7 to 8 in 0,0 i mm. almost 

 parallel. - Nar. sec. A. S. Atl. XLIII f. 13. 



Fresh water: Laconia U. S. A. (Atl.). 



52. P. trigonocephala Cl. N. Sp. — V. linear, gibbous in the middle and at the Vn-oadl}^ 

 cuneate, snbcapitate ends. L. 0,i7 to 0,2; B. 0,02 1; mm. Median line narrow, its central pores 

 approximate. Terminal fi.ssures comma-shaped. Axial area narrow, linear, .slightly dilated in the 

 middle. Strise 7 in 0,01 mm. slightly divergent in the middle and convergent at the ends. Bands 

 not visible. — PI. I f. 21. 



Fresh water: America (Waltham Mass., Hudson River, Del^y Coll., Big Lake S. Calif. 

 Deby Coll.)! 



53. P. conspicua A. S. (187fi). — V. linear, gibbous in the middle and at the ends. L. 0, 11 

 to 0,1. -5; B. 0,0 18 to 0,019 mm. Median line filiform, with approximate central pores and .semi- 

 circular terminal fissures. Area very narrow, slightly dilated around the central nodule. Stria} 

 11 in 0,01 mm. slightly divergent in the middle, elsewhere almost parallel. — Nov conspicua 

 A. S. Atl. XLIII f. 10, 11. 



Fresli water: Demerara River! 



