34 ARKIV FÖR BOTANIK. BAND 14. N:0 9. 



original A. Proteus of Gregory. This is, to judge from Gre- 

 gory's figures, a large species, attaining until 125 [J. in length, 

 though Cleve states only 40 — 65 [x, and distinguished from 

 the closely related Amphora robusta by the ventral striae 

 being interrupted by a blank band, widening towards the 

 centrum. A. robusta has a band of uninterrupted ventral 

 striae generally of equal length along the median lines. In 

 the Knjäsha-samples, I have seen many frustules of what I 

 believe to be a genuine Amphora Proteus, about 80 [J- in length, 

 with 9 coarsely punctate striae in 10 [J.. 



Amphora Proteus Greg. var. Kariana Grun. A. D. 

 Tab. 1, f. 7. 



Foss.: Kk. Knjäsha, rare. 



Distr. {mar.): East Arctic Sea. 



Cleve has not kept this form a distinct variety, but it 

 is smaller than the main form, only 45 [j. in length, and has 

 only a single row of striae, on the ventral side, except near 

 the ends. 



Amphora Proteus Greg. var. contigua Cl. Syn. Nav. 

 D. II, p. 103. A. S. Atl. Tab. 27, f. 7—9. 

 Foss.: Kk. Knjäsha. 

 Distr. North Sea, ubiquist. 



Amphora Proteus Greg. var. tenuissima n. var. — PI. 

 2, f. 41. — Sijn.? Amphora elongata Greg. D. of Clyde, p. 49, 

 Tab. 5, f. 84 (not mentioned in Cleve's Synopsis). 



Frustule narrow, elongated, subrectangular. 70 [j. in 

 length, 17 ;j- in breadth. Striae 9 in 10 [j., formed of trans- 

 apically dilated, coarse puncta. On the ventral side is a 

 narrow, not interrupted band of striae. 



Foss.: Kk. Knjäsha {mar.). 



Amphora Proteus Greg. var. laevistriata n. var. — PI. 

 2, f. 42. 



Frustule elongated-elliptical, 78 [j. in length, 27 [J. in breadth. 

 Striae 10 in 10 |j., not distinctly punctate (obscurely pearled). 

 Ventral striae more irregularly interrupted, at some distance 

 from the median line, except close to the centrale nodule. 



Foss.: Kk. Knjäsha {mar.). 



I 



