16 ASTRID CLEVE, ON RECENT FRESHWATER DIATOMS. 



striae in 0,oi mm. Axial area the fonrtli part of tlie breadth. 

 of the valve. 



Kv. 1. — Rare. 



Var. thermalis Grun. — V. H. XII, 27 a. 

 Valve linear, gibbous in the middle, 0,0 5 5 mm. in length. 

 Striae abont 23 in 0,oi mm. 

 Ks. 15. — Rare. 



C. obtusa W. Sm. — Nav. Hebes Ralfs. Cl. 1. c. p. 54. 



Kv. 9, 16, Nu. 17, Ks. 15, 20, Jm. 6, 31, Tj. 42, Gl. 47, 

 Km. 10. — Rather frequent. 



C. fasciata Lägst. — V. H. XII, 34, Cl. 1. c. p. 50. 

 Ke. 49. — Rare. 



Neidiimi Pfitzer. 



N. Iridis Ehb. — V. H. XIII, 1, A. S. XLIX, 3. 



Forms (mostly small) occur in Jm. 6, Kv. 32. — Rare. 



Var. ampliata Ehb. — A. S. XLIX, 5, Cl. Syn. Nav. p. 69. 

 Jm. 6, Ke. 49. — Rare. 



N. amphi^omphiis Ehb. ~ A. S. XLIX, 9, V. H. XIII, 7. 



Kv. 26, 32, Ks. 15, Tr. 38, Ll. 21. — Not rare. 



N. Hitchcockii Ehb. — A. S. XLIX, 35, 36. 

 Kv. 26, 32. — Rare. 



N. prodiictum W. Sm. — A. S. XLIX, 37—39. 

 Nu. 41, Jm. 31, Tj. 42, Gl. 43. — Not rare. 



N. affine Ehb. 



Var. gemiiiia Cl. — 1. c. p. 6S, A. S. XLIX, 21-23. 



Kv. 26, Ks. 15, Gl. 43. — Somewhat rare. 



Var. amphirhynchus Ehb. — Cl. 1. c, V. H. XIII, 5, forma 

 minor. Lengtb of tbe valve 0,o.5 mm. 



Kv. 32, Nu. 19, Jm. 6, Gl. 43, Gl. D. 45, S.-K. 7. — 

 Somewhat frequent. 



Var. long-iceps Grég. — Cl. 1. c. 



Length of the valve O, o 3 mm. 



V. 12, Km. 30, Gl. 43, Gl. D. 45. — Not rare. 



