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



Var. africana Cl. — V. elliptic-linear, with broad and ronnded ends. L. (),i.5; B. (),2r) mm. 

 Longitudinal lines crossing the stricE in their middle. Stri;e li") in (),oi mm. - PL IV f. 5. 

 Brackish water: Cameroon! 

 The var. africana merits perhaps to be considered as a distinct species. 



50. €, Holsiii Cl. (1881). — V. elliptical, with parallel margins and cuneate ends. L. 0,0.^2 

 to 0,u(;; B. 0,0 IB to 0,o2 mm. Axial area very narrow; central area small, rounded. StriiP 14 in 

 0,0 1 mm. almost parallel, not distinctly or finely punctate. L(mgitudinal lines nmrginal. — A. S. 

 Atl. L. f. 48 (without name). Nov. Holstii Cl. D. f. Gronl. and Argentina p. II 1^1. XVI f. 1. 



Fresh water: Greenland! Albany, Maine, fossil! Oregon (Atl.). 



51. €. Ladogeiisis Cl. (1«91). V. broad, lanceolatt!, with suljrostrate ends. L. 0,o->5; 

 B. 0,0 14 mm. Axial area indistinct; central area small rounded, somewhat transverse. Stripe 17 

 in 0,0 1 mm. slightly radiate, finely punctate. Longitudinal lines marginal, faint. — Nav. Ldihif/. 

 Cl. L. of Finl. p. 35 PI. 11 f. 3. 



Fresh water: Ladoga, on the surface of the lake! 



52. C? (lispersa CIr. and Sturt (1887). — V. almost flat, elliptic-lanceolate, with subacute 

 ends. L. 0,08; B. 0,027 mm. Median line straight, terminating close to the margin. Axial area 

 narrow, dilated in the middle to a small rounded space. Striae 27 in 0,oi mm., finely punctate, 

 puncta forming undulating longitudinal lines. The striu' are confined to an irregular, lanceolate 

 space aroiind the axial area, the part outside of this space being iri'egularly and coarsely punctate. 

 Longitudinal lines inframarginal. — Nav. ilisp. Gu. and Sturt. (^ueck. M. Cl. Ill (2) p. 132 

 PI. X f. 10. 



Marine: Oamaru, N. Zeeland, fossil! 



This is remarkable species, which 1 have placed here only with hesitation. The longi- 

 tudinal line is visible only in strongly oblicpie light. A somewhat^ similar form occurs at 

 Monterey, which 1 know by a sketch sent by Grunow, who calls it Mastogloia? decorata. This 

 form is smaller (L. 0,033; B. 0,oi3 mm.) and has a larger tpiadrate central area and probably 

 coarser strise. 



53. C.'J sejuncta A. S. (1874). — V. linear, with parallel margins and rounded cuneate 

 ends. L. 0,04; B. 0,oi ram. Axial and central areas indistinct. Stria^ 12 in 0,oi mm. transverse. 

 Longitudinal lines broad, submarginal. — Nov. .sejuncta A. S. N. 8. D. p. 87 PI. 1 f. 18. 



Marine: North Sea, Campeachy Bay (A. S.). 



1 have not seen this species, which A. Schmidt seems to consider akin to Diploneis 

 nitescens. It seems to me more probable that it belongs to the grou]) of (J. Fowellii. No indica- 

 tion of the nature of the strite exists. If punctate this form may be a Diploneis; if smooth it 

 belongs to the group of C. Poivdlii. 



54. C. blanda A. S. (1874). — V. linear, with ronnded ends. L. 0,o.'j to 0,i3; B. 0,oi to 

 0,0 18 mm. Axial area narrow. Central area orljicular, large. Stria' 8 to 10 inO,oi mm. parallel, 

 radiate at the ends, not distinctly punctate. Longitudinal lines broad. — A«r. blduda A. S. N. 

 S. D. p. 90 PI. 11 f. 27. Finn, ergadcmis Greg. T. M. S. 1856 p. 48 PI. V f. 2-r^ 



Marine: North Sea! Black Sea! Ceylon! Seychelles! Amboina! Labuan! Tahiti! 



r 



55. C. supei'gr«adata Brun. (1891). — V. convex, linear, with rounded ends. L. 0, ii.-i to 

 0, is.'^i; B. 0,0 16 mm. Axial and central areas combined in a broad, linear space. Median line 

 strongly flexuose. Striae (5 in 0,oi mm., parallel smooth. Longitudinal lines broad, marginal. — 

 Nav. supernr. Brun. D. Esp. n. p. 40 PI. XV f. 6. 



Marine: Gulf of Naples! Port d' Alger (Brun), Bosphorus (Brun). 



