84 p. T. CLEVE, SYNOPSIS OF THE NAVICULOIO DIATOMS. " 



area narrow, widened in the middle to a broad, transverse fascia. Stripe 12 in 0,oi mm. strongly 

 divergent in the middle and convergent at the ends. — Nav. hogotensis A. 8. Atl. XLIV f. 30 to 32. 

 Fresh water: New Grenada (Atl.), French Pond, Maine (Atl.). 



35. P. sabsolaris Grun. (18H2). - V. linear-lanceolate, with obtuse ends. L. 0,o65 to 0,o7 ; 

 B. 0,0 1 to 0,0 14 mm. Median line with bayonet-shaped terminal fissures. Axial area narrow, 

 widened in the middle to a large suborbicular space. Striffi 10 to 11 in 0,oi mm. strongly diver- 

 gent in the middle and convergent at the ends. — Nav. dccurrens? A. S. Atl. XLV f. 29, 30. 

 Nav. Legumen vix undulata V. H. Syn. PI. VI f. 17. Nav. {deccurrens Ehb. vur.?) subsolaris 

 Grun. Foss. D. Oster. Ung. p. 143. Nav. scythica Pant. Ill PI. XXIII f. 335 (1893). 



Fresh water: Norway (Stavanger, foss.)! Scotland! Hungary (Dubravica Dept. Grun.), New 

 Zealand! Canada! Dana's Pond (Grun.), Demerara River! 



Var. hrevistriata Grun. (1882). — Area broader. Stria? less radiate. — Nav subs. var. hr. 

 Foss. D. Osterr. Ung. p. 143 PI. XXX f. 38. 



Fresh water: Hungary (Dubravica Dept. Grun.). 



Var. atistraliensis Cl. — L. 0,09 6; B. 0,oi2 mm. Stripe 14 in 0,oi mm. 



Fresh water: Rieva Lagoons, Australian Alps! 



Var. linearis Cl. — V. linear, with parallel margins and broad, subtruncate ends. L. 0,12; 

 B. 0,0 17 mm. StricB 10 in 0,oi mm. 



Fresh water: Finland (Lojo)! Rangoon! New Zealand! 



36. P. Tsihellariii Ehb. (1843). — V. slender, gibbtais in the middle and at the ends. 

 L. 0,1 to 0,2; B. 0,0 1.^ to 0,02 mm. Median line filiform, slightly oblique, with approximate central 

 pores and bayonet-shaped terminal fissures. Axial area linear, less than '/g as broad as the valve, 

 widened in the middle to an elliptical space. Strite 11 to 14 in 0,oi mm. strongly divergent in 

 the middle, convergent at the ends. — Am. p. 134 PI. II: 1 f. 2ti. M. G. II: ,3 f. 6. Nav Tab. 

 A. S. Atl. XLIII f. 4. 



Fresh water: N. America (Cherryfield, Waltham Mass., Bemis Lake, White Mountains, 

 Crane Pond) S. America, Brazil, Caldas! South Africa, Ombika (Brun Coll.)! 



37. P. mesogongyla Ehb. (1870). — V. linear, gibbous in the middle and gradually tape- 

 ring to the subca2)itate, broad ends. L. 0,o6 to 0,08; B. O,oi:i mm. Median line filiform, with 

 somewhat approximate central pores and slightly curved terminal fissures. Area narrow, widened 

 in the middle to an orbicular space. Strite 11 in 0,oi mm. strongly divergent in the middle and 

 convergent at the ends. — Ber. 187(1 II f. 16. Cl. D. of Finland p. 25 PI. If. 11. Nav. (without 

 name) A. S. Atl. XLV f. 45. Nav. decurrcns Cl. Vega XXXVI f. 20. Nav. gibba V. H. Syn. 

 Suppl. A f. 12. 



Fresh water: Iceland! Scotland, Lock Canmor (Atl.), Finmark! Norway, Dovre! East Cape! 

 Utah (Ehb.). 



Var. intcrrupta Cl. (1891). — L. O,oti; B. 0,oi mm. Stride 12 in 0,oi mm. interrupted by 

 a broad, transverse fascia. — Cl. D. of Finland p. -l^ PI. I f. 10. 

 Fresh water: Finland! 



V. niesogongyla of Ehrenber(J comprises several different species, among which are P. no- 

 biUs and P. major. As the forms figured in Ber. 1X70 seems to be the same as ours, I have 

 adopted Ehrenberg's name. Grunow believes this form to be 1'. (Iccnrrais of Ehrenbbrg, but the 

 latter is too insufficiently figured to admit of identification. ]'. decurrcns seems to be a form of 

 F. atauroptcra. 



38. P. JSilliinaiiorum Ehb. (1843). — V. lanceolate, with large, capitate ends. L. 0,i4 to 

 0,i.'j; B. 0,034 to 0,035 mm. Median line filiform with distant median pores and bayonet shaped 

 terminal fissures. Axial area large, dilated around the central nodule, on both sides of which 

 are some rugosities. Striie 10 in 0,oi mm., strongly divergent in the middle, and there alternately 



