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



{ 



„ , Ends subcapitate N. nuda Pant. 



acute 3. 



3. 



StriiE about 12 in 0,0 1 mm A', lucida Pant. 



— — 17 — N. Schmidtii Lagst. 



— — 24 — N. Acus Ol. 



I _ — 30 — 4. 



J Longituflinal striw closer than the transverse lY. fns'iforiinfi Grun. 



' \ — — more distant N. Franenfeldii Grun. 



. j Ends rostrate '. N. crctssirontris Grun. 



" \ — obtuse or truncate G. 



.. ( Terminal fissures in contrary directions 7. 



' \ — — indistinct iV. Lineola Grun. 



_ j Strise all parallel iV. 'parallelistriata Pant. 



\ Median striae radiate N hetrroflcxa Pant. 



1. N. fusiformis Gri'N. (1877). — V. narrow, lanceolate, gradually tapering from the middle 

 to the acnte end;^. L. O.iis to 0,ir); B. 0,oi mm. Central pores very approximate. Striae trans- 

 verse, 33 in 0,01 mm., longitudinal 36 in 0,oi mm. — Berkeleya Fusidinm Grun. Hedw. 1867 p. 17. 

 Amphiphura danica KtiTZ Bac. p. 103 PI. XXX f. 38 (1844)? N. fus. Grfn. M. J. 1877 p. 178 

 PL CXCV f. 11. 



Marine: Honduras (Grun.). 



Var. ostrearia Gaillon (1820). — L. 0,063 to 0,o73; B. 0,oo6 to 0,oo7 mm. Stria? tran.sverse 

 36 in 0,01 mm. — Vibrio ostreariiis Gaillon (accord, to Grun.). — Nav. ostrearia Tixvp. Diet, d'hist. 

 nat. II PI. I f . 2 (accord, to Grun.). N. fusif. v. ostrearia Grun. M. M. J. 1877 p. 178 PI. CXCV 

 f. 12. V. H. Syn. PI. XIV f. 33. 



Marine: North Sea (West coast of Sweden)! Loire infer. (Grun.), Marseille (Grun.), Triest (Grun.). 



This species lives on oyster-beds and according to Bornet the oysters become greenish by 

 feeding on this diatom. Living frustules have two chromatophore-plates along the connecting zone. 

 The cell-sap has, especially towards the ends, a peculiar blue colour. 



2. N. Franenfeldii Grun. (1863). — V. lanceolate. L. 0,i to 0,i6; B. 0,oi9 to 0,o2 5 mm. 

 Central pores very approximate. Transverse strife 29 in 0,oi mm., longitudinal more distant. — 

 Amphipleura Franenfeldii Grun. Verb. 1863 p. 144 PI. V f. 3. N. Franenf. Grun. M. M. J. 1877 p. 179. 



Marine: Indian Ocean (Grun.). 



3. N. nuda Pant. (1889). — V. narrow, lanceolate, with subcapitate ends. L. 0,0,37 ; B. 0, 007 

 mm. Stripe not observed. — Pant. II p. 51 PI. VI f. 108. 



Brackish water: Hungary, fossil (Pant.). 



This species is unknown to me and tlie description and figure are not sufficient for diagnosis. 



4. N. Aens Cl. N. Sp. — V. narrow, lanceolate, acute. L. 0,09; B. 0,oo9 mm. Central 

 pores approximate. Terminal fissures elongated. Axial and central areas indistinct. Striee 24 to 

 25 in 0,01 mm., e([uidistant, in the middle slightly radiate, elsewhere transverse, or nearly so — 

 PI. Ill f. 29, 30. 



Marine: Balearic Islands! 



As N. Aeus Cl. 1880 (A. D.) is the same as N. inornata Grun. the name Acus may be used 

 for this form, which diff'ers from N. fiisoides Grun. (1880) by the absence of longitudinal lines and 

 by its indistinct area. 



5. N. Sclimidtii Lagst. (1876). — V. narrow, lanceolate, with somewhat obtuse ends. 

 L. 0,06 to 0,074; B. 0,009 to 0,011 nun. Central pores approximate. Striae about 17 in 0,oi mm., 

 transverse. — N. (without name) A. S. N. S. D. PI. Ill f. 7, 8 (1874). N. Schm. Ldt. Boh. D. p. 45. 



Marine: Bohu.slan (Ldt). 



I do not know this species, which seems doubtful. The fig. in A. S. is not sufficient, and 

 the description of La(!ERSTEDT may belong to some form of Nav. (Schizonema) ramosissima. The 



