KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 26. N:0 2. 183 



Fresh water: Sweden! Finland! England! Dubravica, Hungary, foss. (Grun.). Celebes! Hawaji! 

 New Zealand! Australia (Daintree River! Mitchell River! Australian Alps! Tasmania!) Nova 

 Scotia! Illinois! Mexico! Jamaica! Ecuador! 



Var. major (tRUN. (1880). — V. slender, lanceolate. L. 0,o7 to 0,io; B. 0,on mm. Strise 9 

 to 10 in 0,01 mm. distinctly punctate. — GtRUN. in V. H. Syn. PI. XXIV f. 12. G. hebridense 

 Greg. M. J. II PL IV f. 19? 



Fresh water: New Zealand! Rhode Island! Demerara River! 



Var.? lanceolata Kutz. (1844). — V. lanceolate-clavate, with apiculate apex. L. 0,055; 

 B. 0,01 mm. Axial area narrow; central area narrow, transverse. Strise 16 in 0,oi mm. — KtJTZ. 

 Bac. p. 87 PI. XXX f. .59. V. H. Syn. XXIV f. 11. G. Turris var. apiculafa Grun. D. of 

 Banka p. 10 PI. I f. 12. 



Fresh water: Trinidad (Ktitz, Grun.), Banka (Grun.). 



Var. naviculacea W. Sm. (1856). — V. almost symmetrical to the transverse axis, lanceo- 

 late. L. 0,035 to 0,047; B. 0,oo7 to 0,01 mm. Striae 11 to 14 in 0,oi mm., indistinctly punctate. 

 - W. Sm. B. D. II p. 98. V. H. Syn. XXIV f. 13, 14. 



Fresh water: Edinburgh Bot. Garden (W. Sm.)! New Zealand! 



G. gracile comprises a large number of closely connected forms, some of which are nearly 

 akin to G. intricatum, some to G. lanceolatum Ehb. 



8. G. Cymbella Brun (1891). — V. linear, slightly elavate with obtuse apex and basis, 

 slightly lunate. L. 0,05 to 0,o65; B. 0,oii mm. Axial area narrow. Central area transverse not 

 reaching the margin, with a conspicuous stigma. Strise almost parallel 6 to 7 in 0,oi mm. — Brun 

 D. esp. n. p. 28 PI. XIX f. 2. 



Fresh water: South Africa, Rio de la Plata, Cape Horn (Brun). 



9. G. lanceolatum Ehb. (1843). — V. lanceolate, elavate, gradually tapering from the 

 middle to the obtuse apex and basis. L. 0,027 to 0,o7; B. 0,oi mm. Axial area narrow linear. 

 Central area small, rounded, with one unilateral stigma. Strise 12 to 13 in 0,oi mm., slightly 

 radiate, coarsely punctate; puncta 22 to 24 in 0,oi mm.; the median stria opposite to the stigma 

 shortened. — Ehb. Am. PI. II: i f. 37. G. affine Kutz. Bac. p. 86 PL XXX f. 54 (1844). V. H. 

 Syn. PL XXIV f. 8 to 10. G. Szaloi Pant. Ill PL II f. 34 (1893)? 



Fresh water: Mexico! Jamaica! Ecuador! Lake Tacarigua, Trinidad (V. H. Syn.), Marquesas 

 Islands! New Zealand! 



Var. insignis Greg. (1856). — At the type, but with coarser strise, 9 to 10 in 0,oi mm.; 

 puncta 18 to 22 in 0,oi mm. — G. insignis Greg. M. J. IV PL I f. 39. V. H. S. PL XXIV f. 39 to 41. 



Fresh water: Scotland (Greg.), Bengal! Victoria, Australia! Ecuador, San Nicolas! 



Var. hengalensis Grun. (1880). — More elavate. L. 0,o3 to 0,o57; B. 0,oo9 mm. Strise 8 

 to 9 in 0,01 mm. indistinctly punctate. — G. bengalense Grun. in V. H. Syn. PL XXIV f. 37, 38. 



Fresh water: Bengal (V. H. Syn.). 



G. lanceolatum is nearly akin to 6r. gracile, some of its forms being exceedingly difficult to 

 distinguish from several varieties of that species. Some forms are, on the other hand, very similar 

 to forms of G. subclavatum. 



10. G. subclavatum Grun. (1878). — V. elavate, with broad rounded apex and somewhat 

 narrower basis, gibbous in the middle. L. 0,o35 to 0,o7; B. 0,oo8 to O.oi mm. Axial area 

 narrow; central area rounded, with distinct stigma. Strise strong, 9 to 13 in 0,oi mm. obscurely 

 punctate, almost transverse, the median ones often shortened. — G. longiceps Ehb. var. subclavata 

 Grun. Casp. S. Algae p. 10. G. montanum v. subclav. Grun. in V. H. Syn. p. 125 PL XXIII 

 f. 39—43., XXIV f. 1. G. commutatum Grun. V. H. Syn. PL XXIV f. 2. Fr. Jos. Land D. 

 p. 98 (46) PL I f. 12. G. longiceps Ehb. M. G. PL VII: 3, B f. 9 (18,54)? Schum. P. D. p. 187 

 PL ix f. 27? G. Cy gnus' Sir ose Kliecken f. 17. G. calcareum Cl. a. M. D. N:o 137. G. dichoto- 



