KONGL. ÖV. VET. AKADEMIENS HANDLINGAR. BAND 27. 



N:0 



4. A. Macraeana Pant. (1889). — V. rhomboid-lanceolate, gradually tapering to the not pro- 

 tracted eiids. L. 0,ii9 to 0,1?; B. 0,027 to 0,033 mm. Axial area uarrow linear. Central area a 

 transverse fascia, reaching on one side to the margin, on the other nearly to the margin. StrifB 

 18 in 0,01 mm., transverse in the middle and convergent at the ends, composed of elongated 

 puncta forming nndnlating, longitudinal rows, about 14 in 0, 01 mm. — Nav. Macraeana Pant. II 

 Pl. VIII f. 155. 



Brackish water: Hungary, Gyöngyös Påta! 



5. A. menilitica Pant. (1889). — V. lanceolate with rostrate, obtuse ends. L. 0,o38; 

 B. 0,0 16 mm. Axial area linear. Central area a transverse fascia. Striee 20 in 0, 01 mm. com- 

 posed of distant pnncta. — N. menil. Pant. II p. 51 Pl. II f. oO. 



Brackish water: Hungary, fossil (Pant.). 



I have not seen this form, which seems to be nearly akin to A. splicerophora var. hiceps. 

 Nav. irrorafa rar. fossilis Pant. (Pl. VIII f. 147) seems to be also related to the above species. 



6. A.? serians Bréb. (1844). — V. rhomboid-lanceolate with acute ends. L. 0,o6 to O, os; 

 B. 0,012 mm. Axial area linear-lanceolate. Striai 24 in 0, 01 mm. slightly radiate throughout, 

 composed of elongated puncta, forming longitudinal rows. — Navicula serians Bréb. in Kutz Bac. 

 p. 92 Pl. XXX f. 23. W. Sm. B. D. XVI f. 130. Donk. B. D. p. 41 Pl. VI f. 10. Grun. Verh. 

 1860 Pl. V f. 13. V. H. Syn. p. 101 Pl. XII f. 7. N. lineolata Ehb. 1843 fide Kutz. N. punctu- 

 lata Ehb. M. G. XVI: 1, f. 1 1854. 



Fresh water, northern or alpine regions: Greenland! Lapland! Scotland! England, Cornwall! 

 Belgium (V. H.), Switzerland ! Sierra Nevada! New Hampshire (foss.)! Blue Mountains, Aiistralia! 

 New Zealand (foss.)! 



This well-known species occurs rarely living except in notherii or alpine regions. It is of 

 frequent occurence in diatomaceous earths from Scandinavia and North America. 



7. A.? brachysira (Bkéb. 1853) Gkdn. — V. rhomboid, more or less obtuse. L. 0,022 to 

 0.028; B. 0,006 to 0,009 mm. Axial area uarrow; central small. Strise 26 to 27 in 0, 01 mm. — 

 Navicula brachysira Bréb. in Rabh. Sussw. D. p. 39 Pl. V f. 11 c, d, e. Grun. V. H. Types N:o 

 39. C. serians v. minor and minima Grun. in V. H. Syn. Pl. XII f. 8, 9. Cymhella Beverleiana 

 A. S. Atl. LXXI f. 56 to 61 (1881). 



Fresh water: Greenland! Lapland! Finland! Scotland! 



A. brachysira in V. H. Syn. Suppl. B f. 31 seems, so far I cau see, to be the same as A. serians. 

 A. brachysira differs from A. serians only in its smaller size, its somewhat liner strise and espe- 

 cially its obtuse ends. There is a tendency to asymmetry in the valves, which induced A. S. to 

 regard such forms as belonging to Cymbella. 



8. A.? zellensis Grun. (1860). — V. linear, slightly biconstricted, with rostrate, broad and 

 obtuse ends. L. 0,032; B. 0,oo.'j mm. Strise 30 in 0, 01 mm. Axial area indistinct; central small. 

 — Nav. zellensis Grun. Verh. 1860 p. 521 Pl. III f. 34. V. H. Syn. Pl. XII f, 14. N. tabida Ry- 

 LANDS (according to Grunow). 



Fresh water: Germany, Erlaf See (Grun.), Scotland! Greenland! Michigan! 

 This form is nearly conuected with A. brachysira and A. serians. 



9. A.? Follis Ehb. (1838). — V. rhomboid, with strongly dilated middle, and obtuse, usually 

 capitate ends. L. 0,04; B. 0,oi7 mm. Central area small, lanceolate. Strise 24 in 0,oi mm., radiate 

 in the middle, transverse in the ends. — Navic. Follis Ehb. Inf. p. 179 M. G. XVI: 1, f. 14 etc. 

 Donk. B. D. p. 44 Pl, VI f. 15. N. Trochus Kutz Bac. p. 99 Pl. III f. 59. 



Fresh water: Sweden (Lapland, Småland)! Finland! Scotland! Norfolk, England (Donk.) 

 New Hampshire! Sierra Nevada! 



