184 p. T. CLEVE, SYNOPSIS OF THE NAVIOULOID DIATOMS. 



mum /? sessile KtJTZ. (fide Grrun.). G. Brebissonii KuTZ. (fide G-run.). G. mexicanum GrRUN. in 

 V. H. Syn. PL XXIV f. 3. G. Kinlcerianum Pant. Ill PI. X f. 162, 165. 



Fresh water: Sweden! Finland! Holstein! Belgium (V. H.), France! England! Neusidler See 

 (G-run.), Iceland! Argentina! Chimborazo, Ecuador! Sandwich Islands! Tasmania! Auckland! California! 



Var. obliqua Grun. (1884). — Cymbelloid bent, asymmetrical to the longitudinal axis. — 

 Grun. Fr. Josephs L. D. p. (98) 46. 



Var. acuminata HMiB. a. Perag. (1893). — Lanceolate, tapering towards the narrow ends. 



— G. subclav. var. acum. H^rib. a. Perag. D. d'Auvergne p. 55 PI. Ill f. 8. 



Fresh water: Auvergne, fossil. 



Var. Mustela Ehb. (1854). — Biconstricted, with gibbous, obtuse apex. — G. Must. Ehb. M. 

 G. PI. VII: 3, B. f. 9. ScHUM. P. D. p. 187 PL IX f. 30. V. H. Syn. PL XXIV f. 4 to 7. 

 G. Sagitta Schum. P. D. Ill Nachtr. PL II f. 16? 



Fresh water: Beeren Eiland (Lagst.), Finmark! Norway, Dovre! Finland! Gulf of Bothnia! 



Forma curvata Br. a. Perag. (1893). — Frustules in front-view curved. — H^rib. D. d'Au- 

 vergne p. 59 PL III f. 6, 7. 



Fresh water: Auvergne, fossil. 



Var. montana Schum. (1867). — Biconstricted, with protracted subtruncate or obtuse apex. 



— Schum. Tatra p. 67 PL III f. 35. V. H. Syn. p. 124 PL XXIII f. 33 to 36. G. acuminatum 

 var. submontana Gutwinsky F1. Galiz. p. 28 PL I f. 23. 



Fresh water: Galiz. (Schum.), Belgium (V. H.), Hungary, fossil (Grun.), Demerara River! 

 G. subclavatum by its variety montana makes complete transition to G. acuminatum, the 

 latter comprising forms with acute, the former with obtuse ends. 



11. G. acuminatum Fhb. (1838). — V. clavate, more or less biconstricted, with apiculate 

 apex, and narrow basis. L. 0,o3 to 0,07; B. 0,oo9 to 0,oi mm. Axial area narrow or indistinct; 

 central area short and narrow, unilateral. Striae 10 to 11 in 0,oi ram., slightly radiate, the median 

 stria opposite to the stigma being shortened. — Ehb. Inf. p. 217 PL XVIII f. 4. W. Sm. B, D. 

 I PL XXVIII f. 238 a, a'. 



Forma trigonocephala Ehb. (1854). — V. not distinctly biconstricted. Apex cuneate. — 

 G. trig. Ehb. M. G. PL VI: i f. 36. V. H. Syn. PL XXIII f. 18. 



Forma Brebissonii KtJTZ. (1859). — V. slightly biconstricted, with cuneate apex. — G. Breb. 

 KuTZ. Sp. Alg. p. 66. V. H. Syn. XXIII f. 23—26. C. ac. var. Glavus V. H. Syn. PL XXIII 

 f. 20. G. acum. W. Sm. B. D. PL XXVIII f. 238 a'". 



Forma coronata Ehb. (1840). — V. strongly biconstricted, with broad, apiculate apex. — 

 G. coron. Ehb. Abh. 1840 p. 211. G. acum. W. Sm. B. D. PL XXVIII f. 238 /?. V. H. Syn. 

 p. 124 PL XXIII f. 15. Petit Lac des Vosges f. 2. Strose Kliecken f. 16. G. acum.. V. H. Syn. 

 PL XXIII f. 16. 6r. acum. var. laticeps V. H. Syn. 1. c. f. 17. 



Forma pusilla G-run. (1880). • — As the f. coron. but smaller. L. 0,0 3; B. 0,oo8 mm. — 

 G. acum. var. pus. Grun. V. H. Syn. PL XXIII f. 19. 



Fresh water: Spitzbergen (Lagst.), Sweden! Finland! Belgium (V. H.), England, (Sm.), Ger- 

 many! Switzerland! France! Spain! Canada! Massachusetts! Illinois! 



Var. elongata W. Sm. (1855). — V. slender, elongated, strongly gibbous in the middle and at 

 the apex. L. 0,o7 to 0,n; B. 0,oi2 to 0,oi7 mm. Striis 12 in 0,oi mm. coarsely punctate; puncta 

 about 20 in O.oi mm. — G. elongat. W. Sm. Ann. N. Hist. 1855 p. 6 PL I f. 4. B. D. II p. 99. 

 G. acum. var. elong. V. H. Syn. PL XXIII f. 22. G. Brebissonii Greg. M. J. II PL IV f. 13 

 (1854)? G. acum. var. intermedia Grun. in V. H. Syn. PL XXIII £ 21. 



Fresh water: Scotland! Finland! Vosges! 



Var. Turris Ehb. (1843). — V. very slightly biconstricted with cuneate or apiculate apex. 

 L. 0,04 to 0,06; B. 0,oi3 mm. Striae 10 to 11 in 0,oi mm. — G. Turris Ehb. Am. p. 128. M. G. 

 PL XIV f. 70, 71. V. H. Syn. PL XXIII f. 31. 



