192 P. T. CLEVE, SYNOPSIS OF THE NAVICULOID DTATOMS. 



linear, central axial area, on one side of whicli, in the middle of tlie valve, there is a horseshoe- 

 shaped area. Strife 13 in 0,oi mra. almost parallel, coarsely punctate. Lower V. with narrow 

 axial area and broad, qnadrate or rectangular central area. Strise 14 in 0,oi mm., sliglitly radiate, 

 coarsely punctate. — Achnanthidium lanceoJattim Kutz. Sp. Alg. p. 54. "VV. Sm. B. D. II Pl. XXXVII 

 f. 304. Achnanthes laiic. Grdn. A. D. p. 23. V. H. Syn. p. 131 Pl. XXVII f. 8 to 11. Sfauro- 

 neifi frnncata Schum. Preuss. D. I Nachtr. p. 22 f. 28. 



Fresli water: Tlironghout Europé! Amsterdam Island! Tasmania! New Zealand! Australia 

 (North Australia, Daintree River, Australian Alps)! Illinois! Ecuador! 



Var. åuhia Grun. (1880). — Broadly lanceolate. L. 0,oi5 to 0, 017; B. 0,oo7 to 0, 0072 mm. 

 StritE 13 to 14 in 0,oi mm. — A. D. p. 23. V. H. Syn. p. 132 Pl. XXVII f. 12, 13. 



Fresli water: Belgium (V. H.), Austria (Grun.)! 



Var. elliptica Cl. (1891). — EUiptical. L. 0,oi2 to 0,oi6; B. 0,oo7 to 0,oo9 mm. Upper V. 

 with 16 strife in 0,oi mm. — D. of Finland p. 51 Pl. III f. 10, 11. 



Fresli water: Abo in Finland! 



Var. Haynaldii Saaksch. (1881). — Inflated in the middle, with rostrate-capitate ends. L. 

 0,025. to 0,027; B. 0,007 mm. Strife 16 in 0, 01 mm., indistinctly punctate. — Achn. Haynaldii Saarsch. 

 Spec. Phyc. Aequat. p. 8 (according to De Toni Syll. p. 478). Cl. Diatomiste II Pl. VII f. 14. 



Fresch water: Ecuador, Antisana! 



3. A. Peragalli Brun. a. Hérib. (1893). — Broadly elliptical, inflated, with protracted api- 

 culate or subcapitate ends. L. 0,oi2 to 0,oi6; B. 0,oo6 to 0,oo8 mm. Upper V. with narrow, 

 linear and central axial area, on one side of which in the middle of the valve there is a horseshoe- 

 shaped area. Strise 17 in 0, 01 mm. sliglitly radiate. Lower V. with large, ontward dilated central 

 area. Striae very fine and oblique. — D. d'Auvergne p. 50 Pl. I f. 4. 



Fresh water: Puy de Dome, living (Brun. Coll.)! 



A very small, but distinct species, resembling A. lanc. var. Haynaldii. 



4. A. mesogongyla Grun. (1879). — Narrow, elongated, inflated in the middle, with ronnded 

 ends. L. O, os to 0,09; B. 0,oi3 to 0,oi4 mm. Upper V. with central, narrow axial area and 

 transverse, coarsely punctate strife, 10 in 0, 01 mm. (puncta 18 in 0, 01 mm.). Lower V. with broad 

 central fascia. Strife 11 in 0,oi mm. punctate; puncta IS in 0,oi mm. — Cl. M. D. N:o 193. 

 A. D. p. 19. Icon. nost. Pl. III f. 2. 



Fresh water: Brazil! 



5. A. coarctata Beéb. (1855). — Linear, slightly constricted in the middle, with broad, 

 truncate ends. L. 0,04; B. 0,oo8 mm. Upper V. with very excentric, narrow, frequently infra- 

 marginal, axial area. Strife 11 to 14 in 0, 01 ram. punctate. Lower V. with broad central fascia. 

 Stritfi 12 to 15 in 0, 01 ram. slightly radiate, punctate. — Achnanfhidimn coarrt. Ann. Mag. Nat. 

 Hist. [2] Vol. XV p. 8 f. 10. W. Sm. B. D. Pl. LXI f. 379. Achnanthes coarrt Grun. A. V>. 

 p. 20. V. H. Syn. p. 130 Pl. XXVI f. 17 to 20. Achnanthidium coarcf. rar. elinenfa Lagst. 

 Spitsb. D. p. 49 Pl. I f. 16. Achn. hinodis Enn. M. G. Pl. XXXIV, 5, B, 12. 



Fresh water, moist earth, on mosses: Spitsbergen! Beeren Eiland (Lagst.), Arctic America! 

 Sweden (Upsala)! England! France! Belgium (V. H.). 



6. A. infläta Kötz. (1844). — Elongated, gibbous in the middle, witli ronnded capitate ends. 

 L. 0,04 5 to 0,00 5; B. 0,oi5 to 0,oi8 mm. Upper V. with veiy excentric axial area. Striie 9 to 

 10 in 0,01 mm. parallel, coraposed of coarse puncta, abont 9 in 0, 01 mm. Lower V. with broad 

 fascia. Strite abont 10 in 0,01 mm. slightly i'adiate; puncta about 10 in 0, 01 mm. — Stauronei. 

 infläta KDtz. Bac. 105 Pl. XXX f. 22. Achnanthes vcntricom Ehb. M. Geol. p. 226. Monogramma 

 ventr. Ehb. M. Geol. Pl. I, TT, f. 9, Pl. Ill f. 18, 19, /;, c. Grev. T. Bot. Soc. Edinl). Vol. VTII 



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