A. CLEVE-EULER, DIAT. FLORA OF FINLAND. 15 



Foss.: Ab. Hindersmossen (Lüorina-dei^.); Kk. Knjäsha 

 (marine dep.), rare. 



Distr. {mar.): Jutland (0STRur). 



A few specimens seen, that resemble 0strup's figure, 

 but are a little larger (L. 40 "J., Br. 9 a) and have 14 instead 

 of 18 striae in 10 [j.. 



Gyrosigma Hassall. 



Gyrosigma Fasciola (Ehb.). - V. H. Syn. Tab. 21, f. 8. 



Foss.: Ab. Hindersmossen. (Mixed strata from the An- 

 cylus- and Liiorina-e^oc\\s\) 



Distr. {mar.): West and East Arctic Sea, North Sea^ 

 Atlantic and Pacific oceans. 



Naviculae Decipientes Grun. 



Navicula Crucicula W. Sm. var. minor n. var. PI. 1, f. 13. 



Valve elliptic-lanceolate, with broad, truncate, sometimes 

 more protracted ends. Length 30—50 [j., breadth 10 — 13 [i. 

 Axial area undistinct, central nodule transversely dilated a& 

 in N . Crucicula. Striae slightly radiate, not distinctly punctate, 

 very fine except the three or four median ones, that are 

 strong, more distant and shortened. 



Foss.: Ab, Hindersmossen {jresh iv.). 



This form, that is smaller than the typical Nav. Cruci- 

 cula, seems to connect that species with Naii. subinflata Grun. 

 (Cleve Vega-Exp. D. Tab. 37, f. 50). There is some confu- 

 sion in literature about Navicula Crucicula. If the remark- 

 able, transversely dilated central nodule, that is very distinct 

 in Donkin's figure (B. D. T. 6 f. 14) be considered a dominating 

 feature of this species, neither the valve, figured in V. H. 

 Tab. 10, f. 15, nor a variety, drawn by 0strup in Danske 

 Diat. Tab. 1, f. 30 ought to be referred to Donkin's species. 

 The Danish form is perhaps identical with Navicula Lund- 

 strömii var. Frieseana Grun., cfr. Cleve Syn. Nav. D. I, 

 Tab. 5, f. 18. 



Navicula gibbula Cl. var. elliptica n. var. 



Valve linear-elliptic with rounded ends, not truncate a& 

 in the main form, described and figured by Cleve in Syn. 

 Nav. D. I, p. 140, Tab. 5, f 17. 



Foss.: Kk. Niemenkönkään alus; rare {jresh iv.). 



