182 P. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 



Var. dichotoma KuTZ (1833). — L. 0,o4 to 0,o6; B. 0,oo8 mm. Strite 11 to 13 in O.m mm. 

 — G. dichot. KtJTZ. Syn. D. p. 569 f. 48. Bacil. p. 85 Pl. VIII f. 14. W. Sm. B. U. Pl. XXIX 

 f. 241? G. intr. var. dich. V. H. Syn. p. 125 Pl. XXIV f. 30—31. G. pulvhmtum Al. Br. in Rab. 

 Sussw. D. p. 58 (1853). V. H. Syn. f. 32 to 34. 



Fresh water: Finland! Ztiricli! Australia (Victoria, Lake Muir, Tasmauia)! 



Var. fossilib- Pant. (1889). — L. 0,u45; B. 0,oo7.5 mm. Stria; 10 to 12,5 in 0,ui mm., the 

 median more di.stant, 7,.^) in 0,oi mm. — Pant. II p. 5fi Pl. XI f. 201. 



Brackish water: Hungary, foss. (Pant.). 



Var. Vibrio Ehb. (1843). — V. very slender and narrow, Hnear, slightly gibbous in the 

 middle, witli rounded-truncate often gibbous ends. L. 0,08 to 0,oii; B. 0,oi to O.ma mm. Strisp, 

 10 in 0,0 1 mm. distinctly punctate. — G. Vibrio Ehb. Verb. p. 128 Pl. II: i f. 40. Microg. W. Sm. 

 B. D. Pl. XXVIII f. 242. V. H. Syn. Pl. XXIV f. 26—27. G. Cygnus Schum. P. D. p. 187 

 Pl. IX f. 26? 



Fresh water: Finland! Germany, Erlaf See (Grrun.), Hungary, Dubravica. fossil (Grun.), 

 Seychelles! 



To this species probably belongs G. Imngaricum Pant. Ill Pl. II f. 28 (1893). 



5. G. subtile Ehb. (1843). — V. narrow, elongate,d biconstricted, with broad, rounded- 

 truncate apex. L. 0,04 5; B. 0,oo7 mm. Axial area indistinct; central area narrow, unilateral, 

 transverse. Strise 12 in 0,oi mm., almost transverse, distinctly punctate. — Ehk. Am. p. 128. 

 Greg. M. J. IV Pl. I f. 12. Schum. P. D. I Nacht. Pl. II f. 19. V. H. Syn. Pl. XXIII f. 13, 14. 



Fresh water: Scotland! Finland! Holstein! Bengal! 



Var. Sagitta Schum. (1863). — As the type, bnt with cuneate apex. — G. Sagitta Schum. 

 P. D. p. 187 Pl. IX f. 29. V. H. Syn. Pl. XXIII f. 27. 

 Fresh water: Prussia (Schum.). 



6. G. semiapertum Grun. (1880). — V. elongated, clavate, with Ijroad apex and basis. L. 

 0,06 to 0,0-; B. 0,ön to 0,oi3 mm. Axial area distinct, linear; central area a large. transverse 

 fascia, with a distinct stigma on one side and frequently marginal striee on the other. Strife 10 

 to 11 in 0,0 1 mm., slightly radiate, punctate; puncta about 21 in O.oi mm. — Grun. in V. H. Sjai. 

 Pl. XXIV f. 42. Cl. M. D. N:o 264. 



Fresh water: Calitbrnia, Shasta Co (Grun.), Oregon, Pitt River (Grove Coll.)! 



7. G. gracile Ehb. (1838). — V. elongated, linear to lanceolate. with acute to subacute apex 

 and basis. L. 0,025 to 0,o7; B. 0,o4 to O,oiii ram. Axial area very narrow; central area narrow. 

 transverse. Striae transverse, 9 to 15 in 0,oi mm. 



Var. cymbelloides Grun. Ms. — V. slightly asymmetrical to the longitudinal axis, with gently 

 curved doi'sal margin and nearly straight ventral margin. L. 0, 03; B. 0, 005 mm. Strise about 

 16 in 0,01 mm. 



Fresh water: Norway, Dovre! Sweden, Helsingland, Arbrä! 



Var. aiirita Al. Br. (1853). — V. narrow, linear-lanceolate. L. 0, 0:^4 to 'V'-* i K- 0, 005 to 

 0,006 mm. Strise 15 to 16 in 0, 01 mm. Living cells with two horn-like processes at the end. — 

 G. aur. Al. Br. in Rabh. Stissw. D. p. 59 Pl. VIII f. 3. V. H. Syn. XXIV f. 15 to 18. G. an- 

 gustum Schum. I Naclitr. Pl. II f. 17? 



Fresh water: Baden, Titisee (A. Br.). Finland! Norway, Dovre! IcelandI U. St. Bemis Lake, 

 White Mountains! 



Var. dichoiomnm W. Sm. (1853). — Linear-lanceolate, slightlj^ clavate, with obtuse ends. 

 L. 0,04 to 0,05; B. 0,007 mm. Striaj 12 to 14 in 0, 01 mm. finely punctate. — G. dichotomum 

 W. Sm. Br. D. I p. 79 Pl. XXVIII f. 240. G. {gracile var.?) diclwfonmm V. H. Syn. Pl. XXXV 

 f. 19 to 21. G. tcndlum W. Sm. B. D. Pl. XXIX f. 243? G. Vibrio Schum. Tatra Pl. UI f. 38? 

 G. hchridense Hérib. D. d'Auvergne p. 61 Pl. III f. 9? 



