KONGL. SV. VET. AKADEMIENS HANDLINGAK. BAND 27. N:0 3. 183 



This subgenns comprises forms, wliich appear not to be very closely connected. A. hyper- 

 borea seems to be akin to the linear forms of Microneis. A. gihherula and A. Holstii are probably 

 allied to the section Mesoleice of Navicula and oiiglit perhaps to be placed by the side of C. mi- 

 nuta. To C. quarnerensis and the others I am unable to find any allied forms ameng the Naviculce. 



Artificial hey. 



f Valve linear A. hyperborea Grun. 



1. I — lam 



lanceolate or rhomboidal 2. 



I — elliptical 5. 



„ j Area of tlie upper valve granulate A. Lilljebergii Gkun. 



\ — — — — not — 3. 



i> I Upper valve with an horseshoe-like mark A. Vaszaryi Pant. 



\ — — witliout — • — — 4. 



. J Strise of the upper valve 22 in 0,oi mm A. gibberula Geun. 



• I — — — — 14 — — A. Holstii Cl. 



,. I L. about 0,01 mm 6. 



I L. 0,02 mm. or more 7. 



,. ) Strise of the upper valve unilaterally interrupted A. americana Cl. 



' \ — — — — not — — C. pygmcea Schum. 



„ j Upper valve with an horseshoe-like mark > A. Lagerheimii Cr,. 



' \ — — without — — — 8. 



o I Striffi of the upper valve i) in 0,ni ram C. quarnerensis Grun. 



■ 1 — — — — 11 to 12 in 0,01 mm. . . . ' 9. 



9. 



j Area of the upper valve dilated in the middle C. biharensis Pant. 



I — — — — not - — — C. Pelta A. S. 



1. A. Vaszaryi Pant. (1893). — Outline rhomboid, subacute. L. O, os; B. 0,03 mm. Upper 

 V. unknown. Lower V. with narrow axial area and transverse, ontwardly fimbriate central area. 

 Median striiB transverse and of uneqiial lengtli, 13 in 0,oi mm. Other strise strongly radiate 

 throughout, about 20 in 0,oi mm., punctate. — Ifar. Vaszaryi Pant. III Pl. XVI f. 239. 



Habitat? Nyermegy (Pant.). 



Var. oregonica Cl. (1893). — Outline lanceolate with subrostrate, obtuse ends. L. O, os; 

 B. 0,013 inm. Upper V. with lanceolate axial area, a third as broad as the valve, and with a 

 nnilateral horseshoe-shaped marking. CostiB slightly radiate, about IG in 0,oi mm. alternating 

 with fine obliquely ari^anged puncta, about 30 in 0,oi mm. Lower valve without axial area and 

 with a large central area, fimbriate outwards. Median strige of unequal length and transverse, 

 about 18 in 0,oi mm. Strite of the other portions of the valve very radiate, becoming clo.ser 

 towards the ends, about 26 in 0,oi mm. — Piatomiste II p. 57 Pl. III f. 15, 16. 



Fresh water: Oregon, fossil! 



This is a very interesting species, the lower valve of which perfectly resembles that of 

 Actinoneis. It appears to be akin to A. Jteteromorpha of the subgenns Acfinoncis. There can be 

 no doubt that Nav. Vaszaryi .Pant., which represents the lower valve, is very nearly related to 

 the form from Oregon, of which I have examined an entire frustule. The differences are slight, 

 as to the size, the outline, and the coarseness of the striation, for vi^hich reason 1 am not inclined 

 to consider them as distinct species. 



2. A. hyperborea Grun. (1882). — Outline linear, with broad, sometimes cuneate, ends, 

 slightly constricted in the middle. L. 0,o26 to 0, 028; B. 0,oo65 to 0,oo8 mm. slightly arcuate. 

 Upper V. with obsolete median line and broad, linear area. StriiB 27 in 0, 01 mm., radiate at the 

 ends. Lower V. withovit areas. Median strise 24, terminal 30 in 0, 01 mm. — Cl. M. D. N:o 314. 

 Franz Josefs Land D. p. 102 Pl. I f. 4, 5. 



Marine: Franz Josefs Land (Grun.). 



