186 p. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 



1. A. Clevei Grun. (1860). — Lanceolate, obtuse. L. 0,oi3 to 0,024; B. 0,oo6 to 0,oo9 mm. 

 Upper V. with linear, narrow axial area (sometimes with rudimentary central nodule, Grun.). 

 Costse 9 to 11 in 0,oi mm., radiate; intermediate spaces distinctly punctate. Lower V. with very 

 narrow axial area and very small or indistinct central area. Striae 18 to 24 in 0,oi mm. strongly 

 radiate, punctate. Median striee more distant than the others. — A. D. p. 21. V. H. Syn. 

 PL XXVII f. 5, 7. 



Fresh water: Billingen (Westergotland, Sweden)! Gulf of Bothnia at Tornea! 



2. A. bottnica Cl. (1891). — Lanceolate, subacute. L. 0,oi7 to 0,032; B. 0,oo5 to 0,oi 

 mm. Upper V. with narrow, linear axial area, and parallel transverse costse, 11 to 12 in 0,oi 

 mm.; intermediate spaces coarsely punctate (puncta 18 in 0,oi mm.). Lower V. with lanceolate 

 axial area. Striae 17 (middle) to 25 in 0,oi mm., radiate throughout. Among the median strise 

 some shorter ones are frequently intercalated. — A. Clevei var. bottn. — Cl. D. of Finl. p. 52 

 PI. Ill f. 4, 5. 



Slightly brackish water: Gulf of Bothnia, at Tornea! 



3. A. dispar Cl. (1891). — Elliptical or lanceolate, with rostrate ends. L. 0,023; B. 0,oo9 

 mm. Upper V. with linear, narrow axial area. Costse parallel, 19 in 0,oi mm., not distinctly 

 punctate. Median costse abbreviate. Lower V. with indistinct axial area and orbicular central 

 area. Striae about 19 in 0,oi mm. strongly radiate throughout, and in the middle alternately 

 longer and shorter. — D. of Finl. p. 52 PL III f. 2, 3. 



Brackish water: Gulf of Bothnia, at Tornea! 



4. A. inopinata Cl. (1893). — Rhomboid, acute. L. 0,027; B. 0,oo9 mm. Upper V. with 

 narrow axial area and, unilaterally, a horseshoe-shaped marking in the middle. Costse 12 in 0,oi 

 mm. almost parallel, not punctate. Lower V. with narrow axial area and quadrate central area, 

 uniting with lunate lateral areas. Striae 14 in 0,oi mm., radiate, not distinctly punctate. — 

 Diatomiste II p. 57 PL III f. 13, 14. 



Marine: Baldjik (near Varna) fossil! 



5. A. heteroniorpha Grun. (1880). — Rhomboid to lanceolate. L. 0,04 6 to 0,o8; B. 0,02 to 

 0,02 5 mm. Upper V. with narrow axial area and a horseshoe-shaped, unilateral marking in the 

 middle. Costse 8 to 10 in 0,oi mm., slightly radiate, indistinctly (finely Grun.) punctate. Lower 

 V. with broad lanceolate central area. Striae 7 (middle) to 9 (ends) in 0,oi mm. strongly radiate 

 throughout. — A. D. p. 23. Cl. Diatomiste II PL III, 11, 12. 



Fresh water: Demerara River! 



(). A. danica Fl()gel (1873). — Rhomboid, acute. L. 0,036 to 0,05; B. 0,oii to 0,oi5 mm. 

 Upper V. with narrow axial area. Costae 8 to 13 in 0,oi mra. slightly radiate or almost parallel, 

 alternating with fine lineolse, twice as close as the costae. Lower V. , with narrow axial area and 

 transverse central area, fimbriate at the ends. Strise, about 26 in 0,oi mm. strongly radiate 

 throughout, in the middle alternately longer and shorter. — C. danica FlCgel Pommerania D. 

 p. 91 f. 14. Ach. danica Grun. A. D. p. 21 (1880). A. heteropsis Grun. Cl. M. D. N:o 154 (1878). 

 Stauroneis cornuta Lbud. Fortm. D. de Ceylon p. 37 PL III f. 36 (1879). Schisostauron fimhriatum 

 Grun. Hedwigia 1867 p. 28. 



Marine: North Sea (Grip in Norway)! Mediterranean Sea! Adriatic (Grun.), Florida! 



Var. major Cl. — L 0,o7 to 0,08; B. 0,03 to 0,o35 mm. Upper V. with 9 subradiate and 

 anastomosing costse in 0,oi mm. Lower V. with 16 distinctly punctate striae in 0,oi mm. — 

 PL III f. 8, 9. 



Marine: Baldjik, fossil! 



7. A. Lorenziana Grun. (1862). — Lanceolate, subacute. L. 0,04 to 0,05; B. 0,022 mm. 

 Upper V. with narrow lanceolate axial area, and strong, very slightly radiate costae, 7 in 0,oi 



