70 p. T. CLEVE, SYNOPSLS OF THE NAVICULUlD DIATOM.S. 



8. N. dllluiim EiiB. (l.S4o). — V. elliptical, sometimes slightly bieoiistricted, with olitvise. 

 subrostrate, or almost apiciilate ends. L. {),o:\ to 0,0375; B. (),oi mm. Stria; 20 to 21 in 0,01 mm. 

 — Xar. dubia Ehb. Am. p. 130 PI. II f. 2, S. KiJTZ. Bao. p. 06 PI. XXVIIl f. CI. Guw;. .M. .). 

 1856, IV PL I f. 3. SciiuM. P. D. 1 Nacht. p. 21 f. 25. A. S. Atl. XLIX f. 7, s, 24 to 2(1. 

 Nav. Peisonis Grun. Verh. 1860 p. 544 PI. Ill f. 2^. Nav. Iridis var. dubia V. H. Syii. p. 104 

 Suppl. B. f. 32. Nav. incurva var. minuta Gutwinsky Materyjaly p. 22 PI. I f. 18. 



Fresh, sometimes brackish water: Sweden (Westerbotten to Skatie)! Gulf of Bothnia! Scot- 

 land (Greg.). Nensiedler See, Hungary (Grnn.). Bengal! Australia (Blue Mountains)! New Zea- 

 land! North America (Port Hope, Ducks Pond, Lost S])ring Ranch Cal.)! Surinam! Ecuador! Puerto 

 Monte, Chile! Argentina! 



9. N. (lilatatuni Ehb. (1843). — V. broadly elliptical, with subrostrate ends. L. 0,0 6 

 B. 0,()2.'i mm. Strict 16, puncta 17 in 0,oi mm. — Nav. dilatata Ehb. Am. p. 130. A. S. Atl. 

 XLIX f. (i. 



Fresh water: Finland (Vasa! Pudasjarvi Atl.). 



10. N. citrciiin A. S. (1877). — V. broadly lanceolate. L. 0,07 to 0,10; B. 0,04 to 0,o5r, mm. 

 Stria' 16 to 17, puncta 17 to 19 in 0,oi mm. — Nav. cUrea, A. S. Atl. XLIX f. 12. 



Fresh water: Demerara River! 



11. N. iumciscoiis Ghun. (1877). — V. broadly lanceolate. L. 0,i6; B. 0,of, mm. StriiB 16. 

 puncta 17 in 0,oi mm. — Na;v. firma, var. hiDhescohs Grun. A. S. Atl. XLIX f. 10. 



Fresh water: North America (Bemis Lake! Cherryfield! Monmouth! Troy!). 



Additional. 



To Neidium perhaps belongs Nuvicitla indudcns Pant. Ill (PL XIII f. 201). unknown t( 

 the author. 



Pseudoamphiprora Cl. (1881). 



Valve more or less lanceolate and convex. Median line straight. Central nodule transverselv 

 dilated into a stanros, not reaching the margin, luit abutting on two longitudinal lines, one on each 

 side of the median line. Axial area indistinct, central area a transverse fascia. Stri;t nearly 

 parallel, composed of fine })uncta. Connecting zone not complex. — The cell-contents of P. sfauro- 

 pfcra have two chromatophore-plates along the valves. They have entire margins and a deep, 

 narrow sinus from the apices, below the median line. Their substance is thinner below the longi- 

 tudinal lines. 



In the year 1881 (New and rare D. p. 13) I pi'oposed to iuclude in a section Pseudo-amphi- 

 prnra of Navicxila a few forms, among which was Amphora .^fauropfcru Bail., synonymous with 

 Amp)hiprora Icpidoptcra Grkg. (D. of Cl. PL ^ii f. 59 c) and A. obtu.m Greg. (1. c. f. 60). This 

 small group is very interesting and merits to be regarded as a separate genus, the systematic place 

 of which is between Navicidce LyraUe and Caloiwis. 



All the species are marine and inhabit both arctic and tropical seas. 



Artificial kcij of i:ipe(:ies. 



I Stauros narrow P. unplrto Cl. a. Grov. 



\ — broad 2. 



j V. witli cuneate ends F. polygona Beun. 



I V. lanceolate 3. 



