1 2 p. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 



„^ I Central area small or indistinct .... N. multiseriata Grdn. 



■ \ — — orbicular — . . N. maculosa Donk. 



„„ ( Size small. L. 0,015 to 0,04 mm. . . . 37. 



I — large. L. 0,05 mm. and more . . .... 43. 



„_ I Stria! 14 in 0,oi mm. . . . 38. 



\ — 6 to 10 mm .' . . 40. 



.,„ f Median stria stronger ■ N. cincta Ehb. 



^8- t _ _ „„t 39. 



{Ends obtuse . . N. Beckii Pant. 

 — acute N. ammophila GauN. 

 — subcapitate . . .... .... . . . N. cryptocephala Kutz. 



,„ j Striae coarsely lineate 41. 



1 — apparently smooth 42. 



.. ( Valve rhomboidal N. Raphoneis Gkun. 



\ — elliptic-lanceolate N. Formenterce Ch. 



,„ J Terminal striae strongly marked N. hungarica Gbun. 



■ \ — — not — — . . . N. costulata Gbun. 



.„ I Ends protracted 52. 



^'^- \ - not - 44. 



, . j Central area distinct . . . 46. 



**■ 1 - - not- 45. 



.p. /Marine habitat N. spuria Cl. 



\ Fresh water — N- radiosa KtJTZ. 



.„ j Striae coarsely lineate 47. 



^^- \ - finely - 49. 



._ / Marine habitat 48. 



\ Fresh water — . N. vulpina KtJTz. 



48. 



{Yalve narrow lanceolate, not very convex N. pinnata Pant. 

 — broadly — convex N. fortis Greg. 



{Valve not very convex N. avenacea Bb^b. 

 — convex, with conical ends .50. 



I Ends very elevated and compressed N. compressicauda A. S. 



\ — not — — — .... 51. 



{Central area small N. cancellata Donk. 

 — — large N. Centraster Cl. 



J Ends subrostrate, obtuse . . N. viridula Ktiiz. 



\ — non-rostrate . . 53. 



-„ j Ends subcapitate . . N. rhynchocephala KCtz. 



\ — acute .... . N. gotlandica Grtin. 



p, . j Frustule arcuate 55. 



non — 56. 



■{■ 



,,. / Striae about 18 in 0,0 1 mm N. genuflexa Kiiiz. 



■ \ — — 10 — — N. Bolleana Gbun. 



_„ I Striae crossed by lateral areas or blank bands 57. 



^•^- i - not - - - - - 64. 



._ j Striae crossed by a single, narrow area 58. 



■ \ — — — several longitudinal bands 60. 



p,„ J Apiculate N. Galea Bbun. 



\ Non-apiculate 59. 



J Axial part of the valve elevated N. superimposita A. S. 



\ — — — — not — . ... N. Phi Cl. 



59. 



„. j Blank lines straight N. arata Grun. 



61. 1^1^ 



- undulating 61. 



Axial area unilateral 62. 



areas bilateral . . . 63. 



M 



„ J Valve slightly convex . N. imperfecta Cl. 



very — N. monodon Gbun. 



3 slightly convex N. consors A. S. 



very — N. guttata Grun. 



