P. T. Cleve: The Diatoms of Finland. 43 



Var. ladogensis Gl. — Costa? 9 in 0,oi m. m. anastomosing 

 irregularly. Puncta indistinct, 10 in 0,oi m. m. Length 0,0 6 m. 

 m. Breadth 0,0 2 5 m. m. 



PI. II, fig. 9. 



This form seems to come near to D. (Navicula) Domblitten- 

 sis Grun. (D. Ost. Ung. XXX, 60). 



Lad. 85, 86. 



D. finnica (Ehb.) Gl. — Gocconeis Finnica Ehb. M. G. XVII, 



II, 19. 



Valve broadly elliptic, 0,0 5 to 0,0 5 5 m. m. in length and 

 0,0 3 4 to 0,0 3 6 m. m. in breadth. Central nodule small. The fur- 

 rows are equally arcuate and at a considerable distance from the 

 raphe, so that the interior space, confined by the furrows, occu- 

 pies about one third of the valve. The costee are 7 in 0,oi m. 

 m.; the puncta 12 in 0,oi m. m., forming longitudinal lines, cros- 

 sing the costse. 



PL II, fig. 11. 



Ab. 36, Lad. 85, Sb. 4. 



Foss. Nyl. 87, Ta. 94, 95, 98, Ob. 92. 



This species is of frequent occurrence in the diatomaceous 

 earths of Sweden, Scotland, United states and Finland, and retains 

 every where its characteristics, so that it may be regarded as a 

 good species. 



D. Parma Gl. n. sp. — Valve broadly elliptic, 0,0 3 m. m. in 

 length and 0,0 2 m. m. in breadth. Central nodule quadrate. Fur- 

 rows arcuate, equally bent, approximate to the prolongations of 

 the central nodule. Costse 14 in 0,oi m. m.; puncta 20 in 0,oi 

 m. m., forming longitudinal lines, crossing the costse. 



This species has a great resemblance to the preceeding but 

 is only half the size and has twice the number of costse and 

 puncta in 0,oi m. m. 



PI. II, fig. 10. 



I have found this form in the lake Rosslangen (Smaland, 

 Sweden) and from the two finnish localities: Lojo Lake (Ab. 36) 

 and Viando (Sb. 5), exactly similar in all these localities. 



D. Boldtiana CI. n. sp. — Valve oblong-elliptic, 0,0 3 m. m. 

 in length and 0,oi2 m. m. in breadth. Costae 14 in 0,oi m. m. 

 Puncta fine and indistinct. Central nodule quadrate, small. Fur- 



