144 p. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 



„„ j Rows of puncta 7 to 10 in 0,1 mm M. crihro$a Gkun. 



\ - - 14 to 15 - - SI. 



o^ i Loculiferous rim broad M. cocconeiformis Geun. 



' \ — — narrow M. Horwathiana Geun. 



22 I Valve elliptical 23. 



I — lanceolate 24. 



no ( Valve with irregular large puncta M. oamaruensis Cl. 



' \ — — close striae M. ovata Geun. 



9A. I Valve without axial or lateral areas 25. 



t - with - - - 65. 



gp ( Strise crossed by several longitudinal furrows 26. 



^•^- \ _ not _ - - 27. 



an I Valve elliptic-lanceolate or rhomboid M. quinquecostata Geun. 



\ — lanceolate, acuminate M. seriata Cl. 



_ f Puncta in straight longitudinal rows, stronger than the transverse 28. 



\ Transverse rows of puncta stronger than the longitudinal 31. 



„„ j Transverse striae 12 in 0,oi mm M. lineata Cl. a. Geove. 



M — — 17 to 30 in 0,01 mm 29. 



aa I Loculiferous rim distant from the margin M. acuta Gkun. 



' \ — — marginal 30. 



„„ / Central area distinct M. arata Cl. 



' \ — — indistinct ... M. exarata Cl. 



„. I Valve with longitudinal lines parallel to the median line 32. 



■ \ — without — — — — — — 38. 



{Longitudinal lines combined with the central area 33. 

 — — not — - — — 35. 



{Small. L, 0,025 to 0,028 mm M. pumila Geun. 

 Larger. L. 0,04 to 0,095 mm 34. 



{Loculi about 8 in 0,oi mm M. Debyi Cl. 

 — — 5 — — ." M. Braunii Geun. 



{Longitudinal lines close to the median line 36. 

 — — distant from — — 37. 



(Valve elliptic-lanceolate M. apiculata W. Sm. 

 — linear with cuneate ends . , M. labuensis Cl. 



— broad, elliptical, rostrate M. Citrus Cl. 



— lanceolate, rostrate M. baltica Grun. 



{Loculi 4 in 0,0 1 mm M. Pisciculus Cl. 

 — 8 — — ■ . . . M. PeragalU Cl. 



( Loculi of equal size ... 39. 



— — unequal . — 61. 



( Valve very small. L. 0,oi mm ... M. gallica W. Sm. 



I — larger. L. 0,02 mm. and more 40. 



f Loculi few . . 41. 



I — numerous 42. 



.^ j Loculi 2 on each side M. capitata Beun. 



l — 4 — — M. exigua Lewis. 



.„ f Loculiferous rim inside the margin M. paradoxa Geun. (M. Smithii var.). 



' \ — — marginal 43. 



,„ f Valve constricted in the middle M. constricta Cl. 



\ — not — — — 44, 



. . / Valve rostrate or apiculate 45. 



■ t — not — 51. 



,, I Puncta forming almost straight longitudinal rows 46. 



■ ■ 1 — not — — — — — , 48, 



^g j Median line strongly undulating M. undulata Geun. 



' \ — — slightly — or straight 47. 



^^ / Ends rostrate-capitate M. Goesii Cl. 



\ — slightly rostrate M. fallax Cl. 



,„ ) Median line strongly flexuose 49. 



■ I — — slightly — 50, 



33. 

 33. 

 34. 

 35. 



36. 



37, 

 38i 

 39. 

 40. 



