KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 



26. n:o 2. 165 



Var. hercynica A. S. (1875). -^ V. rostrate. L. 0,029; B. 0,oi mm. Strise about 13in0,ol mm. — 

 C. here. A. S. Atl. IX f. 30, 31. C. ahyssinica Grun. in Martelli Florula bogosensis p. 151 PL I f. 3 (1886). 

 Fresh water: Juliushall, Harzburg (Atl.), RingsjOn (Sweden)! Abyssinia (Grun.). 



22. C. lata Gkun. Ms. — • V. slightly asymmetrical, broadly lanceolate, with subrostrate to 

 rostrate ends. L. 0,042 to 0,o.5 6; B. 0,oi6 to 0,oi8 mm. Median line almost straight and central. 

 Axial area narrow, linear, slightly dilated around the central nodule. Strise 9 (middle) to 12 (ends) 

 in 0,0 1 mm. slightly radiate in the middle, almost parallel at the ends, finely punctate. — PI. IV f. 27. 



Fresh or slightly brackish water: Sweden (Gulf of Bothnia at Pitea; Ore sjo, near Boras)! 

 Ladoga! Domblitten, Rostock and Liineburg, fossil! 



This species resembles in outline C. Ehrenbergii, but is much smaller and has less distinctly 

 punctate striae. 



23. C. Cucumis A. S. (1875). — V. broad, with convex dorsal and almost straight or slightly 

 convex ventral margin. Ends rostrate-truncate. L. 0,o7 to 0,09; B. 0,024 mm. Median line almost 

 central, slightly arcuate. Axial area narrow, slightly dilated around the central nodule. Striae 



8 to 9 (dorsal) to 10 (ventral) in 0,oi mm. punctate; puncta 12 in 0,oi mm., more distant on the 

 median ventral striae. — A. S. Atl. IX f. 21, 22. 



Fresh water: Bengal (Atl.), Cameroon! 



24. C. Ehrenbergii Ktixz. (1844). — V. asymmetrical, elliptic-lanceolate, with slightly 

 rostrate, obtuse ends. L. 0,09 to 0,i4; B. 0,o28 to 0,o38 mm. Median line slightly excentric, 

 straight. Axial area narrow, but distinct, slightly dilated around the central nodule. Striae 7 to 



9 in 0,01 mm. slightly radiate throughout, coarsely punctate; puncta 13 to 16 in 0,oi mm. — 

 J^avic. incBqualis Ehb. Inf. PI. XIII f. 18 (1838). Gymh. Ehrenh. KtJTZ. Bac. p. 79 PI. VI f. 11. 

 W. Sm. B. D. I PI. II f. 21. A. S. Atl. IX f. 6 to 9; LXXI f. 74. V. H. Syn. p. 61 PL II f. 1. 



Fresh water: Iceland! Sweden (from Lapland to Skane)! Norway! Finland! England! Bel- 

 gium (V. H.), Paris! Germany! Switzerland! North America (Crane Pond, Lost Spring Ranch, 

 Washington territory, St. Rosa Cal.)! 



Var. delecta A. S. (1875). — V. asymmetrical-lanceolate, with slightly rostrate ends. L. 0,o6 3 

 to 0,085; B. 0,019 to 0,024 mm. Axial area narrow, not, or slightly, dilated around the central 

 nodule. Striae 8 to 9 (middle) to 11 (ends) in 0,oi mm. — Cymi. delecta A. S. Atl. IX f. 17. 

 C. Ehrenbergii var. Atl. LXXI f. 80. C. Ehrenh. var. minor V. H. Syn. II f. 2. 



Fresh wa,ter: ^Greenland! Konigsaue (Atl,), Puerto Monte, Chili (Atl.), Victoria, Splitters 

 Creek (Austr.)! 



25. C. lapponica Grun. (1879). — V. almost symmetrical, sublanceolate, gradually tapering 

 from the middle to the acute ends. L. 0,033 to 0,037; B. 0,oo8 to 0,oo85 mm. Median line almost 

 central, straight. Axial area narrow; central area rather large, rounded. Median striae 16 in 

 0,01 mm., terminal striae about 21 in 0,oi mm., finely punctate. — Grun. in CI. M. D. N:o 271. 

 PL IV f. 28. 



Fresh water: North Iceland! Repats in Gellivare, Lulea Lapmark, fossil, Sweden! 



This species has never been described or figured, but I suppose that Grunow denotes this 

 form, which occurs sparingly in CI. M. D. N:o 271. This species seems to connect C. Cesatii with 

 C. stauroneiformis. 



26. C. stauroneiformis Lagst. (1873). - V. lanceolate, almost symmetrical, with nearly 

 obtuse, attenuated ends. L. 0,o38 to 0,04; B. 0,oo9 to O,oii mm. Median line almost central, 

 straight. Axial area very narrow; central area large, quadrate, somewhat broader outwards, not 

 reaching to the margins. Striae 16 to 17 in 0,oi mm., slightly radiate, finely punctate. — Lagst. 

 Spitsb. D. p. 45 PL 1 f, 15. A. S. AtL LXXI f. 62, 63. 



Fresh water: Beeren Eiland (Lagst.), Spitsbergen! 



