KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 26. N:0 2. 61 



45. C. abnonnis G-kun. (187(S). — V. lanceolate, witli broaci, obtnse ends. L. 0, 028 to 0,055; 

 B. 0,uo7 to 0,009 mm. Axial area very narrow; central area small, orbicular. Median lines wtraight, 

 with approximate central pores, and terminal fissnres turned in oontrary direction. Striae 30 

 (Grunow) to 34 in 0, 01 mm. transverse. Longitndinal lines faint, snbmarginal. — Nav. ahnormis 

 Grun. in Cl. M. D. N:o 142. A. D. p. 46. Cal. abii. Icon. n. Part. IV Pl. I f. 6, 7. 



Marine: Bohuslän, Sweden! 



iC). C. brevis Grev. (1857). ^ V. elliptical, with rostrate, obtnse ends. L. 0,06 to 0,o8; 

 B. 0,0 2 2 to 0,0 3 mm. Median line with distant central pores. Axial area narrow, dilated in the 

 middle to a large, orbicular space. Strife 14 in 0,oi mm., almost parallel, not distinctly pnnctate. 

 Longitndinal lines indistinct. — Nav. brcris Gbeg. T), of Clyde p. 478 Pl. IX f. 4. A. S. N. S. D. 

 Pl II f. 15. DoNK. B. D. p. 19 Pl. III f. 4. V. H. Syn. p. 97 Pl. XI f. 19. — Nav. crassa Gees. 

 M. J. III p. 41 Pl. IV f. 18 (1855)? 



Marine: Spitsbergen! Greenland! Pinmark! North Sea! X^orth Siberian Sea, Cape Uesch- 

 niff! Löfånger, Ångermanland, Sweden, (integlacial deposit)! Sydney (Thiim.)! 



Var. vexans Grun. (1880). — Elliptic-lanceolate, with broad, obtuse ends. — Na.v. brevis v. 

 vexans Grun. A. D. p. 30. A. S. N. S. D. Pl. II f. 14. Nav. brev. v. dliptica V. H. Syn. p. 97, 

 Pl. XI f. 18. 



Marine and brackish: Sea of Kära! Finmark! Japan (striffi 18 in 0,oi mm. Weissfiog. CoU.)! 



Var. distoma Grun. (1880). — V. elliptical, with broad ends. Central pores of the median 

 line distant. Central nodule large, thick. Longitudinal lines distinct, singie or double. 



Forma latior: Broadly elliptical. L. 0,o7s; B. 0,02 6 mm. StritB 13 to 14 in 0,oi mm. — 

 Nav. (brevis var.?) diatoma f. lat. Grun. A. D. p. 31 Pl. I f. 25. 



Brackish water: Sea of Kära (Grun.), Japan! 



Forma angustior: Narrow elliptical. L. 0,o68; B. O,oiy mm. Strife 15 to 16 in 0,oi mm. 

 — Nav. (brevis var.?) diatoma f. ang. Grun. A. D. p. 31 Pl. I f. 26. 



Brackish water: Jamal, Sea of Kära (Grun.). 



Forma bicuneata Cl. — V. with parallel margins and cuneate ends. L. 0,o8 5; B. 0,0 2 9 mm. 

 Strise 14 to 15 in 0,oi mm 



Marine: Japan, fossil (Brun CoU.)! Sydney! China! 



Nav. brevis and its varieties are nearly akin to N. amphisbcena. 



il. C. bottnica Cl. N. Sp. — V. elliptic-lanceolate. L. 0,o.'-i; B. 0,oi8 mm. Central pores 

 distant. Axial area broad, gradually dilated towards the middle, where it expands to a transverse 

 fascia. Striee 22 in 0,oi mm. slightly radiate towards the ends. Longitudinal line faint, margi- 

 nal. — Pl. III f. 42. 



Slightly brackish water: Gulf of Bothnia at Piteå! 



48. C. Lagerheimii Cl. N. Sp. — V. elliptic-lanceolate convex, with obtuse ends. L. 0,04 2; 

 B. 0,009 mm. Axial and central areas uniting in a lanceolate-linear space. Stritt. 17 in 0,oi 

 mm. very slightly radiate towards the ends. Longitudinal lines indistinct marginal, or inframarginal. 



Fresh water: Ecuador, Quito (Lagerheim)! 



49. C. latiiiscula Kutz (1844). — V. elliptical to lanceolate. L. 0,07.5 to 0,09; B. 0,023 to 

 0,03 mm. Axial and central areas uniting in an irregularly lanceolate space. Striaj 18 to 21 

 in 0,01 mm. parallel, finely punctate. Longitudinal lines marginal or inframarginal. — Nav. 

 latiuscula Kutz Bac. p. 93 Pl. V f. 40. Grun. Verh. 1860 p. 534 Pl. IV f. 38. Donk. B. 

 D. p. 27 Pl. IV f. 7. Nav. patula W. Sm. B. D. I p. 49 Pl. XVI f. 139 (1853). V. II. Syn. 

 Suppl. B f. 29. 



Fresh water, larger lakes: Scotland; Sweden: Venern! Mälaren! Baltic, freshwater deposits 

 of the Ancylus-epoch ! Gotland! Switzerland (Lac des 4 cantons, Lac Leman)! 



