54 p. T. CLEVB, SYNOPSIS OF THE NAVICULOIO DIATOMS. - 



1^ I Areas well defined 17. 



' i — not — 19. 



..„ ( Ends of the areas convergent or parallel .A', irrornta Grun. 



\ — — — divergent 18. 



I Areas contracted in the middle X. inhulofa A. S. 



^ — not — — — ^ N. fluitans Brun. 



. I Ends ot the areas pai'allel or divergent X Lyra Ehb. 



\ — — — convergent N- approxiniata Grev. (A'. upectahiUs var.). 



j Lateral areas with a band ot short stride 21. 



20. ■! — — punctate or dotted 24. 



I — — smooth 83. 



„. I Terminal fissures in contrary directions N. vnriolata Ct,. 



I — — the same — 22. 



„y I Puncta twice as close as the strise N. illustra Pant. 



^ \ — and striae equidistant 23. 



„., j Strise about 9 in U,oi ram N. ropiosa A. S. 



' \ — — 14 — N. Sandriana Grun. 



y, ) Axial part of the valve elevated at the ends 25. 



" ' 1 — — — not — — - 26. 



,.- 1 Areas with puncta in short undulating rows , X. venustissitna Kitt. 



I — — irregular puncta X. venusta Jan. 



,p . j Areas narrow X. inhalata var. biharensis. 



I — broad 27. 



„_ ) Areas indentate in the middle X. spectabilis rac. hu)igaricn and var. cxcavnta. 



■ i — not — — — 28. 



o„ j Areas semiorblcular X. oamaruetisis Grun. 



\ — semielliptical 29. 



np j Median portion of the areas smooth A'. Stercus muscarum Cl. 



I — — — — punctate 30. 



„„ j Ends rostrate X. clavata var. indica. 



— non — 31. 



Areas with large dots X. perfectn Pant. (X. Hennedyi vnr. raliginosn and i-nr. 



, XeapoUtana). 



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



irregular puncta 32. 



„ j Axial strise of 2 to 4 puncta X. prmtexta Ehb. [X. Hennedyi var. rircum.'<ecta). 



[ — — — 4 to 8 — X. Schaarschmidtii Pant. 



„„ I Valve constricted in the middle . . . X. clavata rar. exul (X. Hennedi/i var. constricta). 



^•^- "^ not - - - ■ 34. 



Valve rostrate X. clavata Greg. 



( Vah 



r 



Areas contracted in the middle X. spectabilis Greg 



34. . „. 



non — 3.0 



{ 



( L. (I 

 ■ t L. 



^^- ' - not - - - 3(.. 



Areas broad X. Hennedyi W. Sm. 



— narrow 37. 



„_ . L. 0,04 7 mm X. turgidula Pant. 



"09 to 0,1V mm X. irrorata Grev. 



M. I 



1. N. concilians Cl. N. Sp. — V. lanceolate, with subrostrate ends. L. 0,045; B. O.02.1 

 ram. Lateral areas not uniting with the central area, linear or narrow lunate, not sharply defined. 

 Marginal strise 13 to 14 in 0,0 1 mm. Puncta abont 18 in 0,o 1 mm., becoming more distant to- 

 wards the areas. — PI. I f. 25. 



Marine: Honoliiln! 



In thi.s form the lateral areas are separated b_\- 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. 0,03 mm. Strise 12 in 0,oi mm.) 

 and from Madagascar. 



