KONliL. «V. VI-;T. AKADKMIKNS 11 AXDLlN(iAi;. HAM) 26. NIO 2. IIV.) 



radiate; terminal striu' 1.") in 0,i)i mm., slightly convergent; all Hnely })nn('tute. — Eiin. Am. I: -j. 

 f. 17. M. G. XVI, I f. 11? W. Sm. B. IJ. I p. r)0 PI. XVI f. 141. IK.xk. H. D. j). 21 I'l. Ill 

 f. S. A. S. Atl. LXXll f. 1. (tRI'N. Franz .loseitli.s Land 1 ). p. I»!l (17) PI. I t. ;}4. Am,>/uj,rnra 

 Hartvularis Khb. Micr. G. Ill: i, f. 10, 11. 



Fresh water: Franz Josephs liand (Grnii.) Sweden (Ijule l^appmark living, coininoii in post- 

 glacial, lacustrine deposits)! Finland, foss.! England (Hull) Doiik., Germany, Harz (Atl.); Bohemia, 

 Eger fossil! North America: common in diatomaceous earths (Nova Scotia, (Janada West, Wash- 

 ington territory etc.)! 



A\^hat Nav. Semen of Ehrenberg may denote is impossible to decide, as the figures published 

 by EiiRENBERi; cannot be recognized. The figure in W. Smith Brit. Diat. is not good, but leaves 

 little doubt that the author meant the same species, which now is generally believed to be N. Semen. 

 On the other hand there can be no doubt that Antphiproia naviculoides of Ehrenberg is the same 

 species as our N. Semen. N. Semen seems to be a northern species, rarely found living, biit fre- 

 quently in postglacial deposits of Scandinavia and North America, it is not mentioned by Brun 

 as an inhabitant of the Alps, nor by Belloc as occurring in the Pyrenees. Its occurrence in a 

 living state in the Harz is an interesting fact and suggests that it may be a survival from the 

 post-glacial epoch. 



2. N. (Diadesmis) seininoides Cl. & Grove N. Sp. — V. elliptic-lanceolate, with truncate 

 ends. L. 0,02 7 to 0,045; B. 0,01 to 0,oi2 ram. Axial area narrow linear, suddenly dilated to a 

 small, orbicular central area. Strite in the middle 16 in 0,01 mm., alternately longer and shorter, 

 divergent; strite at the ends about 23 in 0,oi mm. slightly convergent, all finely punctate. 



Slightly brackish water: A\^est Indies, Jamaica (Grove Coll.)! Ecuador! 



This small form resembles in outline N. Semen. The frustules form in living state coherent 

 filaments. 



3. N. brasiliaiiii Ch. (ISHl). — V. lanceolate, with subacute ends, often slightly asymmetrical. 

 L. 0,();}.^) to 0,()t;.3; B. (1,012 to (),oi8 mm. Median line straight; its terminal fissures in the same 

 direction. Axial area narrow, linear, somewhat dilated around the central nodule. Strise in the 

 middle 18 in 0,01 mm, divergent alternately longer and shorter; towards the ends 21 to 22 in 

 0,01 mm.; at the ends convergent; all distinctly punctate; puncta (on the median stri^ about 18 

 in 0,01 mm.) forming undulating, longitudinal rows. — Cyinhella hra.siJ. Cl. N. R. D. p. 4 PI. 1 f. 4. 



Fresh water: Brazil! Calif. (St. Rosa in Grove Coll.)! Ecuador in mineral springs at Tesalia 

 Prov. Pichincha! 



4. N. inflata Donk. (1870). — V. lanceolate with capitate ends. L. 0,022 to 0,026 ; B. 0,oo7 

 to 0,008 mm. Axial area indistinct, central area small, irregular. Stria; in the middle 19 in (),oi 

 mm., somewhat divergent and of unequal length; other stria; 22 to 23 in 0,oi mm., convergent at 

 the ends, all indistinctly punctate. — Donk. B. D. p. 21 PI. Ill f. 9 (nee Kiitz. = X. hunyarica?) 

 Cl. D. of Finl. p. 37 PI. II f. 2 (1891). 



Fresh water: IrelamI (Lough Mourne foss. Donk.), Sweden (Lake Posslangen in Kalmar 

 Ian, Rimforsa in Westergotland)! Finland, foss.! N. America (Houghton, Michigan, foss.)! 



5. N. ramphoides Pant. (1889). — V. narrow, rhombic-lanceolate, with acute ends, very 

 convex. L. O.ose to O.o'.i; B. O.oi:i mm. Median line with approximate central pores. Axial area 

 indistinct. Central area (by the distant median striae) a narrow transverse fascia. StricE about 

 14 in 0,01 mm. (the median more distant) very slightly radiate, at the ends transverse, indistinctly 

 punctate. — Pant. II p. 53 PI. V f. 97, 98. 



Brackish water: Hungary, fossil! 



f). N. Crucicula W. Sm. (1853). — V. lanceolate to elliptic-lanceolate, with somewhat obtuse 

 ends. L. 0,04,^) to 0,07; B. 0,oi.=) to O,oiy mm. Central nodule transver.sely dilated. Axial and 



