54 



P. T. OLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 



16. 



17. 

 IJS. 

 19 



20. 



31. 

 22. 

 23. 

 24. 

 25. 

 26. 

 27. 

 28. 

 29. 

 30. 



31. 



32. 

 33. 

 34. 

 35. 

 36. 

 37. 



Areas well defined J. . .'♦.•■^ari. . 17. 



— not — 19. 



Ends of the areas coiivergent or parallel j\^. irrorata Geun. 



— — — divergent 18. 



Areas contracted in the middle N. inhalata A. S. 



— not — — — N. fluitans Bbun. 



Ends of the areas parallel or divergent N. Lyra Ehb. 



— — — convergent N. approxintata Grev. (N. spectabilis var.). 



Lateral areas with a band of short striie 21. 



— — punctate or dotted 24. 



— — smooth 33. 



Terminal fissures in eontrary directions N. variolata Cl. 



— — the same — . 22. 



Puncta twice as close as the stri» JV. illustra Pant. 



— and strise equidistant 23. 



Striae about 9 in 0,oi mm N. copiosa A. S. 



— — 14 — N. Sandriana Grun. 



Axial part of the valve elevated at the ends 25. 



— — — not — — — 26. 



Areas with puncta in short undnlating rows N. venustissima Kitt. 



— — irregular puncta N. venwsta Jan. 



Areas narrow N. inhalata var. hiharensis. 



— broad 27. 



Areas indeutate in the middle N. spectabilis var. hilngarica and var. excavata. 



— not — — — 28. 



Areas semiorbicular N. oamaruensis Geun. 



— semielliptical 29. 



Median portion of the areas smooth N. Stercus muscarum Cl. 



— — — — punctate . .' 30. 



Ends rostrate N. elavata var. indica. 



— non — 31. 



Areas with large döts N. perfecta Pant. (N. Hennedyi var. caliginosa and var. 



Neapolitana). 



— — short, undulating rows of puncta JV. reticulo-radiata. Br. a. Temp. 



— — irregular puncta 32. 



Axial strise of 2 to 4 puncta N. prcetexta Ehb. (N. Hennedyi var. circwmsecta). 



— — — 4 to 8 — N. Schaarschmidtii Pant. 



Valve constricted in the middle . . . N. elavata var. exul I.N. Hennedyi var. consfricta). 



— not — — — ' 34. 



Valve rostrate N. elavata Gbeg. 



— non — 35. 



Areas contracted in the middle iV. spectabilis Greg. 



— not — — — 36. 



Areas broad N. Hennedyi W. Sm. 



— narrow 37. 



L. 0,047 mm N. twrgidida Pant. 



h. 0.09 to 0,17 mm N. irrorata Grev. 



1. N. concilians Cl. N. Sp. — V. lanceolate. with subrostrate ends. L. 0,u45; B. 0,o23 

 mm. Lateral areas not uniting with the central area, linear or narrow luiiate, not sharply defined. 

 Marginal striae Vå to 14 in 0,oi mm. Piineta about 18 in 0,0 1 mm., becoming more distant to- 

 wards the areas. — Pl. I f. 25. 



Marine: Honolnln! 



In this form the lateral areas are separated by a row of pnncta from the small central 

 nodule. It is therefore to be considered as a transitional form from the Punctatae to the Lyratae. 

 Similar forms are known from Samoa (lanceolate. L. 0,066; B. 0,o;5 mm. Striai 12 in O, ni mm.) 

 and from Madagascar. 



