KO.VGL. SV. VKT. AKADEMIENS HANDLINGAR. BAND 26. N:0 2. 175 



Cymbella helvetica is a very comraon species, easily recognized by its straight terminal 

 fissures. Under tlie name Encyonema Gerstenbcrgeri Grunow has described (Bänka D. p. 9 Pl. I 

 f. 11; 1865) a form, remarkable for the termiuations of tlie median line, wliich are iinusually distant 

 from the ends of the valve. I have seen from various localities several specimens closely agreeing 

 with the figure published by Grunow, and I have convinced myself that these are abnormal forms 

 of C. helvetica. 



* C. bevesensis Pant. (1889). — V. boat-shaped, with obtuse ends. L. 0,o62; B. 0,oi.3 mm. 

 Median line bent; its central pores very distant. Axial ax'ea narrow, slightly dilated around the 

 central nodule. Striffi 11,5 to 13,5 in 0,oi mm. slightly radiate, pnnctate. — Pant. II p. 40 

 Pl. III f. 53. 



Brackish water: Hungary, fossil (Pant.). 



This species is nnknown to me. The fig. and de.scription given by Pantocsek are insnfhcient 

 for deciding as to its relations to other boat-shaped Cymbellai. 



* C. Chyzerii Pant. (1889). — V. boat-shaped, with the ventral margin slightly gibbons in 

 the middle. Ends snbrostrate, obtuse. L. 0,o825; B. 0,oi45 mm. Median line arcuate, its central 

 pores approximate. Axial area narrow, not dilated in the middle. StriiB 10 to 12,5 in 0,oi mm. 

 Ventral striaj crossed by »a black line><?) — Pant. II p. 40 Pl. XI f. 194. 



Brackish water: Hnngary, fossil (Pant.). 



This species is nnknown to me. The description and the figure given by Pantocsek are 

 insufficient for ascertaining its relations to other boat-shaped Cymbellse. It may come near to 

 C helvetica, C. lanceolata, C. cynihiformis. 



59. C. aspera Ehb. (1840). — V. boat-shaped, with strongly arcuate dorsal margin and 

 straight, centrally gibbous ventral margin. Ends obtuse, rounded. L. O, is to O, is; B. O, o 3. -3 mm. 

 Median line arcuate. Axial area linear, slightly dilated in the middle. Striee 7 to 9 in 0,oi mm. 

 slightly radiate, punctate; puncta 12 to 15 in 0,oi mm. No row of isolated puncta oii the ventral 

 side. — Coccon. aspermn Ehb. Ber. 1840 M. G. V: i f. 1 etc. Petit Journ. de Microgr. 1878 Mars et 

 Avril f. 3. Hérib. D. d'Auvergne Pl. III f. 10. Cy. lanceol. var. aspera Brun D. des Alpes p. 57 

 Pl. IX f. 1(3? Cy. gastroides Kdtz. Bac. p. 79 Pl. VI f. 4 I (1844). A. S. Atl. IX f. 1, 2; X f. 7. 

 V. H. Syn. p. 63 Pl. II f. 8. Grun. Franz Josephs Land D. p. 97 (45) Pl. I f. 7. C. giguntea Pant. 

 III Pl. XXI f. 321 (1893)? 



Fresh water: Franz Josephs Land (Grun.), Iceland! Norway (Dovre, Laurgaard)! Sweden 

 (Lapland to Skåne)! Finland! France! Britain! Belgium! Germany! Switzerland! Savoy! Italy! 

 Japan! New Zealaud! 



Var. minor V. H. (1880). — Smaller, with strongly arcuate median line. L. O, o 7 to O, os 

 mm. — Cy. gastr. forma minor V. H. Syn. p. 63 Pl. II f. 9. 



Var. neogena Grun. (1882). — L. 0,175; B. 0,o33 mm. Strite about 8 in 0,oi mm., 12 in 0,01 

 mm. towards the ends, punctate; puncta about 14 in 0,oi mm. — Cy. gastroides var. neogena Grun. 

 Foss. D. Öster. Ung. p. 141. 



Fre.sh water: Hungary, fossil (Grun.). 



Var. dubravicensis Grun. (1882). — L. O, i6s; B. 0,027 mm. Terminal nodules very strong, 

 at some distance from the ends, surrounded by short stritE. Strite 6 to 9 in 0,oi mm.; their 

 puncta 14 to 17 in 0,oi mm. — Cy. gastr . var. dtibr. Grun. Foss. D. Öster. Ung. p. 141 Pl. XXIX 

 f. 30. Pant. III Pl. XVn f. 251. 



Fresh water: Hungary, fossil (Grun.). 



Var.? crassa Grun. (1882). — V. short and broad with rounded obtuse ends. L. 0,073; 

 B. 0,0 24 mm. Median line strongly arcuate. Axial area narrow. Striee 6 or 7 (middle) to 9 

 (ends) in 0,oi mm. punctate; puncta 16 to 17 in 0,oi mm. The strife are on the ventral side 

 crossed by a short depression. — Grun. Foss. D. Öster. Ung. Pl. XXIX f. 28. 



Fresh water: Hungary, fossil (Grun.). 



