KONGL. SV. VKT. AKADEMIENS HANDLINGAR. BAND 27. N:0 3. 189 



Var. pusilla Grun. (1880). — L. 0,oi3 to 0,oi7; B. 0,oo3 to 0,oo4 mm. Stria; 18 to 23 in 

 0,0 1 mm. — A. D. p. 23. V. H. Syn. PL XXVII f. 33, 34. 



Fresh water: Greenland! Norway (Dovre)! 



Var. JacMi Rabh. (1861). — Broader. L. 0,oi5; B. 0,oo45 mm. Strige about 25 to 26 in 

 0,0 1 mm. — Achnanthidium JacMi Rabh. Alg. E. N:o 1003. V. H. Syn. PI. XXVII f. 24. 



Fresh water: Baden (Rabh.)! 



4. A. exilis Kt)TZ. (1833). — Linear-lanceolate, with rounded ends. L. 0,oi5 to 0,o3; 

 B. 0,008 to 0,009 mm. Upper V. with narrow, axial area slightly dilated at the middle. Striae 

 parallel, about 21 in 0,oi mm. Lower V. without axial area and with small and rounded central 

 area. Strise sliglitly radiate throughout, in the middle 20, at the ends 27 in 0,oi mm. — Dec. 

 N:o 12 (according to Lagst.). Grun. A. D. p. 22. V. H. Syn. PI. XXVII f. 16 to 19. A. subhun- 

 garicum GuTw. Materialy p. 29 PL I f. 26? 



Fresh water: Belgium (V. H.), Germany! 



5. A. glabrata Grun. (1863). — Linear, with rounded ends. L. 0,oi2 to 0,o46; B. 0,oo68 

 to 0,013 mm. Upper V. with 12 to 13 striae in 0,oi mm. Lower V. with 13 to 15 striae in 0,oi 

 mm. coarser in the middle than elsewhere. Frustule with broad connecting zone, and rudimentary 

 diaphragms at the ends. — Verb. 1863 p. 146 PL IV f. 17. A. D. p. 22. 



Marine: California (01. M. D. ]Sr:o 120), Pacific Ocean, New Zealand, North and South Ame- 

 merica (Grun.). 



Var. nuUandica Grun. (1880). — L. 0,035 to 0,04 mm. Strise 22 to 24 in 0,oi mm. Median 

 strife more distant, 10 to 11 in 0,oi mm. — A. D. p. 22. 



Marine: Auckland (Grun.). 



Akin to this species is probably the incompletely described and figured Cymbosira minutula 

 Grun. (Verb. 1863 p. 146 PL IV f. 27). 



6. A. Biasolettiana Kutz. (1844). — Broadly lanceolate, with obtuse, rounded-truncate ends, 

 somewhat gibbous in the middle. L. 0,os5 to 0,o3i ; B. 0,oo65 to 0,oo7 mm. Upper V. with narrow 

 linear axial area. Strise parallel, about 25 in O.oi mm. Lower V. without axial area; central 

 area small, rounded. Striaj 25 in 0,oi mm. slightly radiate in the middle. — Synedra Bias. Kutz. 

 Bac. p. 63 PL III f. 22. Achn. Bias. Grun. A. D. p. 22. V. H. Syn. p. 130 PL XXVII f. 27, 28. 



Fresh water: Hungary (Grun.), Belgium (V. H.). 



Forma minuta Grun. (1880). — L. 0,oi2 to 0,oi3; B. 0,oo45. Striae 24 in 0,oi mm. — 

 A. D. p. 22. 



Fresh water: Triest (Grun.). 



Var. sublinearis Grun. — Linear, narrowed at the ends. L. 0,oi4; B. 0,oo4 mm. Striae 17 

 to 22 in 0,01 mm. — V. H. T. N:o 11. 



Brackish water: Belgium (V. H. T.). 



7. A. tieniata Grun. (1880). — Frustule scarcely arcviate. V. linear, with rounded ends. 

 L. 0,02 to 0,03; B. 0,oos mm. Lower V. without areas. Striae about 24 in 0,oi mm. more distant 

 in the middle and closer towards the ends. — A. D. p. 22 PL I f. 5. 



Marine: Sea of Kara (Grun.). 



8. A. Hudsonis Grun. (1881). — Linear-lanceolate or subelliptical, with broad and obtuse, 

 frequently' subrostrate, ends. L. 0,01.") to 0,o35; B. 0,oo5 to 0,oo8 mm. Upper V. with narrow, 

 linear axial area and parallel striae, 15 to 16 in 0,oi mm. Lower V. with narrow axial area; 

 small and orbicular or subrhomboidal central area. On each side of the central nodule is a lunate 

 marking. Striae 14 in 0,oi mm., slightly radiate. — V. H. Syn. XXVII f. 25, 26. 



Brackish water: Hudson River! 



