14 P. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 



( Habitat: fresh-water N. gracilis Ehb. 



\ — marine 95. 



(3 to 4 times longer tlian broad 96. 

 4 to 6 — — — — N. transitans Cl. 



^°' ' 6 to 7 — — — — N- Zostereti Geun. 



i 10 — — — — N. directa W. Sm. 



„„ ( Valve rbomboidal N. superba Cl. 



\ — lanceolate N. gelida Getjn. 



f Strise between the margin and tbe axis faint 98. 



97. < — unilaterally crossed by an area 99. 



I — crossed by undulating, blank bands 100. 



p„ J Central nodule a short stauros N. finmarchiea Cl. a. Grdn. 



\ — — not stauroid N. transitans v. derasa (N. kariana v. detersa). 



I Valve about 10 times longer tban broad N. directa v. Ineus. 



' \ — — 5 to 6 — — — N. transitans v. incudiformis. ' 



j Valve very convex 101. 



■ 1 — not - loa. 



j Valve fnsiform N- vitriscala Brun. 



\ — linear N. mediterranea Be. a. Cl. 



f Valve linear with cnneate ands N. trigonocephala Cl. 



\ — lanceolate N. transitans v. erosa. 



Lineation oblique N. Eepesii Gkun. 



straigbt 104. 



103. {^^"_1' 



. . I Valve narrow lanceolate JV. ramosissima Ag. 



\ — broadly — N. Kariana Geun. 



1. N. cryptocephala Ktlxz. (1844). — V. lanceolate, with rostrate-capitate ends. L. 0, 025 

 to 0,035; B. 0,00.^ to 0,007 mm. Axial area indistinct. Central area small, somewhat transverse. 

 Strife 16 to 18 in 0,oi mm., radiate in the middle, sligMly convergent iu the ends, finely lineate. 

 — Bac. p. 95 Pl. III f. 26. Donk. B. D. p. 37 Pl. V f. 14. V. H. Syn. p. 84 Pl. VIII f. 1, 5. 

 Nav. mutica Rabh. Alg. Sachs. N:o 965. 



Fresh water: Sweden! England! Belgium (V. H.), Germany! France ! Arctic America ! Green- 

 land! Argentina! Japan! 



Var. veneta Kutz. (1844). — Smaller, with scarcely capitate ends. L. 0,025; B. 0,oo5 mm. 

 Strise 14 in 0,oi mm. — N. veneta Kutz. Bac. p. 95 Pl. XXX f. 76. Pedicino Ischia Pl. II f. 9 

 to 12? Donk. B. D. p. 43 Pl. VI f. 13? iV. cnjpt. v. veneta V. H. Syn. p. 85 Pl. VIII f. 3, 4, 

 Pl. XIV f. 34. 



Brackish water: Sweden, Malmö! Venice (Kutz). 



Var. pumila Grun. (1880). — V. rhombic-lanceolate. L. 0,oi6 to 0,023; B. 0,oo6 to 0,oo7 

 mm. Striaj abont 15 in 0,oi mm. — V. H. Syn. Pl. VIII f. 6, 7, XIV f. 35. N. Ehomhulus 

 ScHUM. P. D. II N. p. 56, Pl. II f. 35 (1867)? iV^. Lancettula Schdm. P. D. II N. Pl. II f. 34. 

 N. cryptoc. v. Lancettula V. H. Syn. Pl. VIII f. 11. N.pumila v. fossili^ Pant. III Pl. V f. 75 (1893)? 



Brackisch water: Triest! 



Var. perminuta Gbun. (1880). — V. lanceolate, not capitate. L. 0,oo8 toO.ou; B. 0,oo3 mm. 

 Striee about 20 in 0,oi mm. — V. H. Syn. Pl. XIV f. 7. 



Var. exilis KiJTZ (1844 p. p. accord. to Grunow). — V. lanceolate, with subrostrate, obtuse 

 ends. L. 0,oi8 to 0,oi9; B. 0,005 mm. StritB about 19 in 0,oi mm. — V. H. Syn. p. 85 Pl. VIII f. 2, 4. 



Fresh water: Belgium (V. H.), Somme! Triest! 



2. N. gotlaiulica Grun. (1878). — V. narrow, lanceolate, with protracted, subacute ends. 

 L. 0,05 to 0,06; B. 0,008 mm. Axial area indistinct; central area small, orbicular. Stri;c 14 

 (middle) to 18 (ends) in 0,oi mm. radiate in the middle, convergent in the ends. — Cl. M. 1). 

 N:o 161. V. H. Syn. Pl. VIII f. 8. 



Slightly brackish water: Sweden, (4otliland! Tasmanial 



' iV. irregidaris Pant. N. sujyerha v. dlijitica. 



