188 p. T. CLEVE, SYNOPSIS OF THE NAVICULOII) DIATOMS. ' 



P. XXIX f. 244. V. H. Syi). p. 126 PL XXV f. 20 to 27. G. sphanelloides Schum. Pr. i). 1 

 Nachtr. p. 19 f. 1(5. (}. suhramosum KuTZ. (tide Grun.). Sphenella vulgaris KtJTZ. (fide Grrun.). 



Fre.sh and brackish water: Sweden! Germany! Switzerland! England! 



Var. haltica Cl. (1^68). — V. clavate. L. 0,04; B. 0, 007.5 mm. Central area small. Stria? 

 16 to 17 in 0,01 mm. — G. haUicum Cl. Sv. och Norsk 1). p. 231 PI. IV f. 10 to 16. 



Brackish water: Baltic (from Westerbotten to Gothland)! 



Var. calcarea Cl. (186S). — V. clavate; L. 0,022 to 0,047; B. 0,oo5 to 0,oo8 mm. Central 

 area small. Stria? 12 to 13 in (),(ii mm. — G. calcareum Cl. Sv. och Norsk I), p. 231 PI. IV f. 7. 



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



Var. stauroneiformis Grun. (1878). — V. lanceolate. L. 0,0:5.3 to 0,07; B. 0,oi to 0,012 mm. 

 Stria; 10 to 13 in 0,oi mm. — Grun. Casp. See Alg. p. 9 PI. Ill f. 2. 



Brackish water: Caspian Sea (Grun.). 



Var. tenellum KtJTZ. (1844). — V. small, clavate. L. 0,012 to 0,025; B. 0,oo:} to 0,00.35 mm. 

 Striae 14 in 0,oi mm. — G. ten. Kutz. Bac. p. S4 PI. VIII f. 8. V. H. Syn. PI. XXIV f. 22 to 25. 



Fresh water: Finland, Abo! Australian Alps! 



G. oJirocexm 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 1 suppose to be 

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

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

 Is a small G. infricatum. 



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

 basis. L. 0,o2 to 0,02i<; B. 0,002 to 0,0035 mm. Axial area indistinct; central area a broad trans- 

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

 mentary diaphragms. — Cl. Diatomiste Vol. II p. 55 PI. Ill f. 4. 



Marine: Hastings (Comber Coll.)! 



24. a. exiguum Kutz. (1844). — V. narrow, clavate with obtuse, sometimes slightly rostrate 

 apex. L. 0.009 to 0,03; B. 0,002 to 0,003 mm. Axial area narrow, not dilated in the middle. 

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

 f. 34. G. hyalinnm Heib. Cousp. D. D. p. 96 PI. V f. 18 (1863). G. exiguum. var. digitatnm V. H. 

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

 f. 38; iHir. 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 difference 

 except in the number of the stria-, and the size. 



Var. paehyclada BrSb. (1838). — V. linear-clavate. L. 0,oi5 to 0,034; B. 0,oo5 mm. Striae 

 16 in 0,01 mm. — G. pack. Bri5b. Consider, p. 21 (fide Chase). V. H. Syn. XXV f. 31, 32. 



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



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

 Stria 16 to 20 in 0,oi mm. almost transverse. — G. ard. Grun. V. H. Syn. PI. XXV f. 30. 

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



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



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

 rower basis. L. 0,03 to 0,07; B. 0,005 to O.oii mm. Axial area distinct, linear, dilated around 

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



