184 p. T. CLEVfi, SYNOPSIS OF THE NAVICULOID DIATOMS. 



3. A. gibbenila Grun. (1880). — Lanceolate, with obtuse ends. L. 0,oi8 to 0,02; B. 0,oo45 

 to 0,00.') ram. Upper V. with wide, lanceolate area. Strise 22 inO,oi mm. Lower V. with narrow, 

 lanceolate axial area, centrally not transversely dilated. Strise about 22 in 0,oi ram. radiate, 

 more distant in the middle than towards the ends. In the zonal view the upper raargin of the 

 lower valve is gibbous in the raiddle. — A. D. p. 22. V. H. Syn. PI. XXVII f. 47 to 49. 



Hot springs: East Indies (Grun.). 



Var. angustior Grun. — Valves narrower. — V. H. T. N:o 139. 



Fresh water: Stuttgart. 



4. A. Holstii Cl. (1881). — Lanceolate, with obtuse, subrostrate ends. L. 0,028; B. 0,oo9 

 rara. Upper V. with broad and lanceolate axial area. Striae 14 in 0,oi ram. subradiate in the 

 middle, parallel at the ends. Lower V. with very narrow axial area, dilated in the middle to a 

 central area not reaching to the margin. Strise 13 (middle) to 14 or 15 (ends) in 0,oi mm., ra- 

 diate. — D. from Greenl. and Arg. p. 13 PL XVI f. 6, 7. 



Fresh water: Greenland, Kornak! 



5. A. margiuulata Grun. (1880). — Elliptical. L. O,oii to 0,022; B. 0,005 to 0,oo8 mm. 

 Upper V. with broad, lanceolate area. Striae 24 in 0,oi mm. marginal. Lower V. with very 

 narrow or indistinct axial area. Central area large, quadrate. Striae 23 to 27 in 0,oi mm. — 



A. D. p. 21. V. H. Syn. PI. XXVII f. 45, 46. Achnanthidium delieatulum Schdm. Tatra p. 61 

 PL II f. 22? 



Fresh water, alpine regions: Arctic America! Greenland! Norway (Dovre)! Russian Lap- 

 land (Fiskarehalfon). 



6. A. americana Cl. (1893). — Broadly elliptical with obtuse or subtrnncate ends. L. 0,013; 



B. 0,006 mm. Upper V. with broad, lanceolate area and about 16 striae in 0,oi mm., unilaterally 

 interrupted. Lower V. with lanceolate area. Striae about 17 in 0,oi mm., radiate and shortened 

 in the middle of the valve. — Diatomiste II PL III f. 17, 18. 



Fresh water: Crane Pond, North America! 



7. C. biharensis Pant. (1889). — Elliptical. L. 0,023 to 0,o26; B. 0,oi3 to 0,oi6 mm. 

 Upper V. with lanceolate area, transversely dilated in the middle, and distinct median line. Striae 

 11 to 12,5 in 0,01 mm. radiate. Lower V. with marginal, costate and radiate striae, 8 to 12,5 in 

 0,01 rara. and with a row of parallel striae (12,5 in 0,oi mm.) along the median line, separated 

 from the marginal striae by narrow lateral areas. — Pant. II p. 57 PL V f. 90, 94. 



Marine: Bory, Hungary (Pant.). 



Var. minor Pant. (1889). — L. 0,oi6; B. 0,08 mm. Upper V. with a row of short striae, 11 in 

 0,01 mm., at some distance from the margin, and enclosing a broad, lanceolate area without median 

 line. Lower V. with 11 striae in 0,oi mm., reaching to the median line. — Pant. II PL IV f. 75, 76. 



Marine: Hungary, fossil (Pant.). 



8. C. pygmaea Schum. (1864). — Broadly elliptical, with rounded ends. L. 0,oo7 to O,oii 

 mm. Striae 15 in 0,oi rara. Upper V. with broad, lanceolate area. Lower V. with narrow area. 

 — Preuss. D. I Nachtr. p. 19 PL II f. 11. 



Brackish water: Baltic (Schum.). 



9. C. Pelta A. S. (1874). — Broadly elliptical. L. 0,02; B. 0,i)i5 mm. Upper V. with 

 broad, lanceolate area. Striae 12 in 0,oi mm. marginal. Lower V. with straight median line. — 

 N. S. D. p. 93 PL III f. 17. Atl. CXCI, 6 to 9. 



Marine: North Sea (A. S.). 



10. C. quarnerensis Grun. (1862). — Elliptical. L. 0,022 to 0,035; B. 0,012 to 0,oi6 mm. 

 Upper V. with very large, usually irregularly punctate area. Striae 9 in 0,oi mm., marginal, not 



