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



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

 New Zealand! Anstralia (Daintree Eiver! Mitehell River! Anstralian Alps! Tasmania!) Nova 

 Scotia! Illinois! Mexico! Jamaica! Ecuador! 



Yar. major (tRun. (1880). — V. slender, lanceolate. L. O, ut to O, lo; B. 0,(iii mm. Strite 9 

 to 10 in 0,0 1 mm. distinctly pnnctate. — Grx'N. in V. H. Sjni. Pl. XXIA'' f. 12. G. hchridensf 

 Geeg. jVI. J. II Pl. IV f. 19? 



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



Var.? lanceolain Kutz. (1844). — V. lanceolate-clavate, witb apinulate apex. L. 0,055; 

 B. 0,111 mm. Axial area narrow; central area narrow, transverse. Stri* IG in 0,iii mm. — KiiTZ. 

 Bac. p. 87 Pl. XXX i. .ö9. V. H. Syn. XXIV f. 11. G. Tiirris rar. apindata Grun. D. of 

 Bänka p. 10 Pl. I f. 12. 



Fresh water: Trinidad (Klitz, Ginm.), Bänka (Gran.). 



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

 late. L. 0,035 to 0,047; B. 0,007 to 0,01 mm. Strise 11 to 14 in 0,ui mm., indistinetly punetate. 

 - 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 closeiy connected forms, some of which are nearly 

 akin to G. iiitricatuni. some to G. lanceolatum Ehb. 



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

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

 reaching the margin, with a conspicuous stigma. StricC almost parallel 6 to 7 inO,oi mm. — Brun 

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



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



9. G. lanceolatmii Eiic. (1843). — V. lanceolate, clavate, gradually tapering from the 

 middle to the obtuse apex and basis. L. 0,02 7 to 0,07; B. 0,oi mm. Axial area narrow linear. 

 Central area small, rounded, with one unilateral stigma. StricC 12 to 13 in 0, 01 mm., slightly 

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

 shortened. — Ehb. Am. Pl. II: 1 f. 37. G. affine KtJTZ. Bac. p. 86 Pl. XXX f. 54 (1844). V. H. 

 Syn. Pl. XXIV f. 8 to 10. G. S.mboi Pant. III Pl. II f. 34 (1893)? 



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

 Islands! New Zealand! 



Var. insignis Greg. (18.Ö6). — At the type, but with coarser strite, 9 to 10 in 0,oi mm.; 

 puncta 18 to 22 in 0,oi mm. — G. iiisignia 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 clavate. L. 0,o3 to 0,05?; B. 0,oo9 mm. Striai 8 

 to 9 in 0,01 mm. indistinetly punetate. — G. bengalense Grun. in V. H. Syn. Pl. XXIV f. 37, 38. 



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



G. lanceolatum is nearly akin to (t. gracile, some of its forms being exceedingly difRcult to 

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

 to forms of G. suhdavatum. 



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

 narrower basis, gibbous in the middle. L. 0,035 to 0,07; B. 0,oo8 to O.oi mm. Axial area 

 narrow; central area rounded, with distinct stigma. Stria' strong, 9 to 13 in O.oi mm. obscurely 

 punetate, almost transverse, the median ones often shortened. — G. longicejjs Ehb. rar. .suhclarata 

 Grun. Casp. S. Alg» p. 10. G. monianum v. stihdav. Grun. in V. H. Syn. p. 125 Pl. XXIII 

 f. 39—43., XXrV f. 1. G. commutahim 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 (1854)? Schum. P. D. p. 187 

 Pl. IX f. 27? G. Ciignns Ströse Klieeken f. 17. G. calcareitm Cl. a. M. D, N:o 137. G. dichoto- 



