KONGL. SV. VET. AKADEMIENS HANDLINGAH. BAND 27. N:0 3. 7 



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

 tracted ends. L. 0,ii9 to 0,i7; B. 0,027 to 0,o33 mm. Axial area narrow linear. Central area a 

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

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

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

 PI. VIII f. 155. 



Brackish water: Hungary, G-yongyos Pata! 



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

 B. 0,016 mm. Axial area linear. Central area a transverse fascia. Striae 20 in 0,oi mm. com- 

 posed of distant puncta. ^ N. menil. Pant. II p. 51 PL 11 f. 30. 



Brackish water: Hungary, fossil (Pant.). 



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

 Nav. irrorata var. fossilis Pant. (PI. VIII f. 147) seems to be also related to the above species. 



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

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

 composed of elongated puncta, forming longitudinal rows. — Navicula serians Br^b. in Kutz Bac. 

 p. 92 PI. XXX f. 23. W. Sm. B. D. XVI f. 130. Donk. B. D. p. 41 PL VI f. 10. Grun. Verb. 

 1860 PL V f. 13. V. H. Syn. p. 101 PL XII f. 7, N. lineolata Ehb. 1843 fide KtJTZ. N. punctu- 

 lata Ehb. M. G. XVI: i, 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, Australia! 

 New Zealand (foss.)! 



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

 frequent occurence in diatomaceovis earths from Scandinavia and North America. 



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

 0.028; B. 0,006 to 0,009 mm. Axial area narrow; central small. Striae 26 to 27 in 0,oi mm. — 

 Navicula brachysira Br^b. 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. Cymbella 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 can see, to be the same as A. serians. 

 A. brachysira differs from A. serians only in its smaller size, its somewhat finer striae 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.? zelleiisis Grun. (1860). — V. linear, slightly biconstricted. with rostrate, broad and 

 obtuse ends. L. 0,032; B. 0,00.5 mm. Striae 30 in 0,oi mm. Axial area indistinct; central small. 

 — Nav. sellensis Grun. Verb. 1860 p. 521 PL III f. 34. V. H. Syn. PL XII f, 14. N. tabidaRr- 

 lands (according to Grunow). 



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

 This form is nearly connected 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. Striae 24 in 0, 01 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 PI, VI f. 15. N. Trochus Kutz Bac. p. 99 PL III f. 59. 



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

 New Hampshire! Sierra Nevada! 



