18 ASTRID CLEVE, ON RECENT FRESHWATER DIATOMS. 



C. angustata W. SxM. — Lagst. Spitsb. pl. II, 10. 



Of this species I have found specimens with distinctly 

 oblique median line. 



Jm. 6, Ks. 15. — Rare. 



C. borealis Cl. — Finl. pl. II, 19. 



Jm. 31, Gl. 43. — Rare. 



Oiily found before in Rnssian Lapland. (Cl. Syn. Nav. 

 p. 1()1). 



C. (lelicatula KtJTZ. — A. S. LXXI, 54. V. H. VI, (), Cl. Syn. 

 Nav. p. 161. 

 Tr. 38. — Rare. 



C. leptoceras (Ehb.?) Grun. —V. H. Suppl. A, 2, Cl. 1. c. p. Ili2. 

 Ke. 49. — Rare. 



C. amphicephala Naeg. — V. H. II, 6, Cl. 1. c. p. 164. 



Kv. 32, Jm. 6, Ks. 15, S.-K. 7. Gl. 43. — Moderately 

 frequent. 



C. lapponica Grun. — Cl. Syn. Nav. pl. IV, 28. 

 Nu. 41. — Rare. 



C. iiaviculiformis AuERSW. — V. H. II, 4, 5, C. anglica Lagst. 

 Spitsb. pl. II, 18. 

 Kv. 1, 2(], 32, 34, Km. 10, 30, Tr. 38, V. 12, Gl. D. 44. 



— Somewbat frequent. 



C. cuspidata KtJTZ. — V. H. II, 3, A. S. IX, 50. 



Kv. 1, 2Q, 32, Jm. 6, 31, Ks. 15, Tr. 38, Gl. 43, Ke. 49. 



— Ratber frequent. 



C. heteropleura Ehb. — A. S. IX, 5, 6. 



Kv. 9, 2S, Nu, 5, 17, 19, 37, 41, Jm. 6, 31, Km. 10, Na. 35, 

 Ks. 20. — Frequent. 



Var. minor Cl. — 1. c. p. 167, A. S. IX, 51, 52. 



Kv. 32, Nu. 5, 18, 19, 41. — Somewbat frequent. 



Var. lanceolata A. Cl. n. var. — Pl. I, 11. 



Valve almost symmetrical, lanceolate, witb scarcely ro- 

 strate ends, 0,09 to 0,i mm. in lengtb, 0,oi8 to 0,025 mm. 

 in breadtb. Axial area distinct, somewbat broader towards 

 tbe middle of tbe valve, wbere it is dilated, more on tbe 



