188 p. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 



P. XXIX f. 244. V. H. Syn. p. 126 PL XXV f. 20 to 27. G. sphcenelloides Schum. fr. D. I 

 Nachtr. p. 19 f. 16. G. subramosum KiJTZ. (fide Grim.). Sphenella vulgaris KtJTZ. (fide Grun.). 



Fresh and brackish water: Sweden! Germany! Switzerland! England! 



Var. baltica Cl. (1868). — V. clavate. L. 0,o4; B. 0,oo75 mm. Central area small. Striae 

 16 to 17 in 0,01 mm. — G. balticum Cl. Sv. och Norsk D. p. 231 PI. IV f. 10 to 16. 



Brackish water: Baltic (from Westerbotten to Gothland)! 



Var. calcarea Cl. (1868). — V. clavate; L. 0,022 to 0,047; B. 0,od5 to 0,oo8 mm. Central 

 area small. Striae 12 to 13 in 0,oi mm. — G. calcareum Cl. Sv. och Norsk D. p. 231 PL IV f. 7<. 



Fresh water (on moist limestone-rocks): Gothland! 



Var. stauroneiformis Grun. (1878). — V. lanceolate. L. 0,o33 to 0,07; B. 0,oi to 0,012 mm. 

 Striae 10 to 13 in 0,oi mm. — Grun. Casp. See Alg. p. 9 PL III £ 2. 



Brackish water: Caspian Sea (Grun.). 



Var. tenellum KtJTZ. (1844). — V. small, clavate. L. 0,oi2 to 0,025; B. 0,oo3 to 0,oo35 mm. 

 Striae 14 in 0,oi mm. — G. ten. KtJTZ. Bac. p. 84 PL VIII f. 8. V. H. Syn. PL XXIV f. 22 to 25. 



Fresh water: Finland, Abo! Australian Alps! 



G. olivaceum lives usually in rivulets by slender stalks attached to stones and forming 

 brownish masses about 1 centim. in diameter. The var. calcarea was found on limestone-rocks on 

 Gothland, fixed by long stalks and forming thick gelatinous masses. The var. baltica is common 

 in the Baltic and the Gulf of Bothnia, where it occurs attached by elongated gelatinous stalks to 

 Zostera and Potamogeton. The G. tenellum is not quite clear to me. What I suppose to be 

 KtJTZiNGs species is doubtless a very small G. olivaceum, but in the Syn. of Van Heurck Grunow 

 places G. tenellum among the asymmetrical Gomphonemas, so it is possible that G. tenellum KtiTZ. 

 Is a small G. intricatum. 



23. G. Aestuarii Cl. (1893). — V. linear, narrow, slightly clavate, with obtuse end and 

 basis. L. 0,02 to 0,02s; B. 0,002 to 0,0035 mm. Axial area indistinct; central area a broad trans- 

 verse fascia. Striae parallel (the median radiate) 20 in 0,oi mm. Ends of the valve with rudi- 

 mentary diaphragms. — Cl. Diatomiste Vol. II p. 55 PL III f. 4. 



Marine: Hastings (Comber Coll.)! 



24. G. exignnm Ktiiz. (1844). — V. narrow, clavate with obtuse, sometimes slightly rostrate 

 apex. L. 0,009 to 0,03; B. 0,oo2 to 0,oo3 mm. Axial area narrow, not dilated in the middle. 

 Striae 18 in 0,oi mm. transverse. — KtJTZ. Bac. p. 84 PL XXX f. 58. V. H. Syn. p. 126 PL XXV 

 f. 34. G. hyalinum Heib. Consp. D. D. p. 96 PL V f. 18 (1863). G. exiguum var. digitatum V. H. 

 Syn. f. 35, 36 ;i var. telographicum (KtJTZ.) V. H. 1. c. f. 37; var minutissimum (KtJTZ.) V. H. 1. c. 

 f. 38; var. perpusilla Grun. V. H. 1. f. 39. 



Marine: Coasts of Denmark (Heib.), England! Belgium (V. H.). 



This minute species is probably widely distributed, but from its smallness rarely met with in 

 cleaned materials. Between the many varieties in V. H. Syn. I am unable to find any diff'erence 

 except in the number of the striae, and the size. 



Var. pachyclada Br^b. (1838). — V. linear-clavate. L. 0,oi5 to 0,034; B. 0,oo5 mm. Striae 

 16 in 0,01 mm. — G. pack. Bntn. Consider, p. 21 (fide Chase). V. H. Syn. XXV f. 31, 32. 



Marine: Coasts of Normandy (Breb., Grun.), Cape "Wankarema! Behrings Island! 



Var. arctica Grun. (1880). — V. broad, clavate. L. 0,02 to 0,035; B. 0,oo6 to 0,oo8 mm. 

 Striae 16 to 20 in 0,oi mm. almost transverse. — G. arct. Grun. V. H. Syn. PL XXV f. 30. 

 Franz Josephs Land D. p. 102 (50) PL If. 13. 



Marine, arctic regions: Franz Josephs Land (Grun.), Nova Zambia! Cape "Wankarema! 



26. G. kamtschaticum Grun. (1878). — V. elongated, clavate, with rounded apex and nar- 

 rower basis. L. 0,03 to 0,07; B. 0,oo5 to O,oii mm. Axial area distinct, linear, dilated around 

 the central nodule. Striae 12 to 16 in 0,oi mm. radiate in the middle, very finely punctate. — 



