70 v. T. CLEVE, SYNOPSIS OK THE NAVICUEUID JJIATuMS. 



8. N. diibiiim Eiib. (]J^4o). — V. elliptical, Horaetimes slightly luioji.stiiLted. with obtuse. 

 subrostrate, or almost apiculate ends. L. O.os to 0,0375; B. O.di mm. Stria' 20 to 24 in O.ui mm. 

 — Nav. dubia Eiiu. Am. p. 130 Pl. 11 f. 2, 8. Kuxz. Bao. p. f)() Pl. XXVIII f. 61. Grkc;. ,^I. .). 

 1856, IV Pl. I f. o. ScuuM. P. D. 1 Nauht. p. 21 f. 25. A. S. Atl. XLIX f. 7, 8, 24 to 26. 

 i\^«(.'. Peisonis Grun. Verh. 1860 p. 544 Pl. Ill f. 28. Nac. Iridis var. dubia V. H. Syn. p. I04 

 Suppl. B. f. 32. Nav. iucurva var. minuta Gutwinsky Materyjaly p. ii Pl. I f. 18. 



Fre.sli, sometimes bracki.sli vvater: Sweden (Westerbotten to Skäne)! (lulf of Bothnial Scot- 

 land (Greg.). Neusiedler See, Hniigary (Grun.). Bengal! Australia (Blue ]\Iouiitains)I Xew Zea- 

 laiid! North America (Port Hojje, Ducks Pond, Löst Spring Raueli Cal.) I Surinam! Ecuador! Puerto 

 Monte, Chile! Argentina! 



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

 B. 0,025 mm. Ötria' 16, puncta 17 in 0,01 mm. — Nav. dilutala EnB. Am. p. 130. A. S. Atl. 

 XLIX f. 6. 



Fresh water: Finland (Vasa! Puda.sjärvi Atl.). 



10. N. citreuin A. S. (1877). — V. broadly lanceolate. L. 0,07 toO,i(i; B. O.04 to 0,005 mm. 

 Strise 16 to 17, puncta 17 to 19 in 0,oi mm. — Nav. cifrea A. S. Atl. XLIX f. 12. 



Fresh water: Demerara River! 



11. N. tuiiiescoiis Grun. (1877). — V. broadly lanceolate. L. 0,i6; B. 0,o6 mm. Stria» 16. 

 puncta 17 in 0, 01 mm. — Nav. firma var. funwseeiis Grun. A. S. Atl. XLIX f. 10. 



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



Additional. 



To Neidium perhaps belongs Naviciila indadtiis Pant. III (Pl. XIII f. 201). unknown te. 

 the author. 



Pseudoampliiprora Cl. (1881). 



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

 dilated into a stauros, not reaching the margin, biat abutting on two longitudinal lines, oue on each 

 side of the median line. Axial area indistinct, central area a transverse fascia. Stritv nearl^- 

 parallel, composed of iine puncta. Connecting zone not complex. — The cell-contents of P. stauro- 

 pttra 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- 

 tiidinal lines. 



In the year 1881 (New and rare D. p. 13) I proposed to include in a section Pseudo-amphi- 

 prora of Navicula a few forms, among which was Ainphora stanroptcra Bail., synonymous with 

 AmpUprora kpidoptcra Greg. (D. of Cl. Pl. XII f. 59 c) and .1. ohfusa 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 Naviauhe LyraUe and Caloneis. 



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



Artiflcial kcij of ajiccicii. 



j I Stauros narrow J'. iiiiph-fa Cl. a. Grov. 



\ — broad •>, 



y ( V. with ciuieate ends p. polygona Brun. 



] V. lanceolate 3. 



