94 P. T. CLEVK, SYNOPSIS OF THE NAVICULOID DIATOMS. 



broad, linear. Central area a transverse fascia, reaching to the margin. Strifs parallel, 7 to 7,5 

 0,01 mm. — Pl. I f . 16. 



Slightly brackish water: Sweden (postglacial deposit of Ebbetorp in Kalmar Län)! Mouth 

 in of Delaware! Connecticut! 



69. P. cardinalis Ehb. (1840). — V. linear, with broad, rounded ends. L. 0,i5 to 0,2; 

 B. 0,03 to 0,03.^ mm. Median line distinctly complex, central pores approximate, terminal fissures 

 comma-shaped, small. Axial area wide; central area a broad transverse fascia, reaching to the 

 margin. Strise 5 in 0, 01 mm., slightly divergent in the middle and convergent at the ends, erossed 

 by a broad band. — Stauroptcra cardinalis Ehb. Berl. Abh. 1840 p. 213 (accord. to Chase). Finnul. 

 cardinalis W. Sm. Br. D. I Pl. XIX f. 166. Nav. cardinalis A. S. Atl. XLIV f. 1, 2. Y. H. Syn. 

 p. 74 Suppl. Pl. A f. 5. 



Fresh water: Sweden (Lapland to Småland foss.)! Finland! Ireland, Scotland (Loch Leven, 

 Ordie Deposit), Belgiiim (V. H.), Italy (Livorno, Atl.). Switzerland (Brun). 



IX, Marinse. 



Ärtificial Jcey. 

 .. j Asymmetrical 2. 



\ Symmetrical 3 



Strise strongly radiate P. Staimtonii Geun. 



— slightly — P. ambigua var. Digitus A. S. 



j Axial area broad 4. 



{ 



3. > . ,. . 



iiarrow or indistinct o. 



, 1 Valve narrow P. amhigua Cl. 



\ — broad P. Tcmperei Brun. 



j. , Central nodule stauroid P bistriata Ledd. Poetm. 



' ■* not — 6. 



. I Centi 



'• i - 



j Central area large, orbicular 7. 



\ — — a transverse fascia 10. 



erossed by a blank band 8. 



( Striffi 



7 , 



not — — — 9. 



I Valve linear P. Trevelyana Donk. 



\ — lanceolate P. Grcenlandica Cl. 



p , Striae 3 to 4 in 0,0 1 mm P. excellens Cl. 



I Stria 



8 to 10 — — P. rectangidata Greg. 



f Valve biconstricted P. Claviculiis Greg. 



10. < — constricted in the middle 11. 



I — not or slightly constricted in the middle 12. 



.. J L. 0,1 mm P lobata Grove a. Stdrt. 



|L, about 0,035 mm P. constricta Cl. 



..,, J Axial area indistinct 13. 



\ — — narrow 14. 



..,, I Striie parallel P. quadratarea A. S. 



I — radiate in the middle, convergent at the ends P cruciforniis Donk. 



.. I Striaj 12 in 0,oi mm P. cruciata Cl. 



1 — 15 to 20 — P Jtoridana Cl. 



70. P. ambigua Cl. N. Sp. — V. linear, with rounded ends. L. 0,033 to 0,o7 8; B. 0,oo7 

 to 0,008 mm. Central nodule small, terminal Jiodulcs small, approximate to the margin. Area 

 broad, linear, not widened in the middle. Stria'. short, parallel, 8 to 9 in 0,oi mm., with capitate 

 terminationw. — Nav. retiisa Grun. A. L). p. 38 (1880). Cl. Vega p. 470 Pl. XXXVl f. 35. 



Marine: Ly.sekil (Bohuslän, Sweden, Grun.), Oldenburg (Grun.), Cape Wankarema! 



The frnstule is according to Grunow, in the zone-view more or less constricted in the 

 middle and more or less broad. The connectiiig zone has nunierous punctate longitiulinal divisions 



