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



61. C. Castracanei Grun. (1881). — V. broadly linear to lanceolate, with obtuse ends. 

 L. 0,07 to 0,135; B. 0,02 to 0,03 mm. Median line straight, with small, terminal nodules and large 

 qviadrate, central nodule. Axial and central areas uniting in a narrow, lanceolate space. Striae 

 9 to 12 in 0,01 mm., slightly radiate throughout, smooth. Longitudinal lines broad, area-like, 

 median, not united with the central area. 



Var. Philippinarum Cl. — V. linear with gradually narrowed ends. L. 0,ii; B. 0,02 mm. 

 Strise 12 in 0,oi mm. 



Marine: Manilla (Deby Coll.). 



Var. Fetitiana GrRUN. (1881). — V. broadly linear, with cuneate ends and parallel margins. 

 L. 0,07; B. 0,02 mm. Area crossed by faint striae. Striae 11 in 0,oi mm. — JS'av. Pet. G-run. in 

 Cl. N. E. D. p. 12 PI. Ill f. 34. 



Marine: Cebu! 



Var. seychellensis Grun. Ms. — Like var. Petitiana, but without faint striae on the area. 

 Striae 10 in 0,oi mm. 



Marine: Seychelles (Van-Heurek Coll.)! 



Var. caledonica Cl. — V. narrow elliptical. L. 0,135; B. 0,03 mm. Striae 10 in 0,oi mm. 



Marine: New Caledonia (Kinker Coll.)! 



Var. genuina Cl. — V. lanceolate. L. 0,i; B. 0,03 mm. Striae 9 in 0,oi mm. — Nav. 

 Castracanei Grun. in Cl. N. R. D. p. 12 PI. Ill f. 33. 



Marine: Australia (Grun.). 



C. Castracanei is a large and beautiful form, and is connected by intermediate varieties with 

 C. Poivellii. 



62. C? venusta Pant. (1889). — V. linear, with rostrate ends. L. 0,037; B. 0,o95 mm. 

 Axial area narrow. Central area small, dilated on both sides of the median line to broad lateral 

 areas. Striae 21 to 22,5 in 0,oi mm., parallel, divergent towards the ends. Longitudinal lines mar- 

 ginal. — Nav. venusta Pant. II p. 54 PL V f . 81. 



Marine: Hungary, fossil (Pant.). 



I have not seen this species; the description being made from the figure in Pantocseks 

 work, which shews some likeness to a small C. PowelUi, with the striae crossed by a narrow, 

 marginal line. 



63. C. arnica Cl. a. Grun. (1881). — V. broad, slightly constricted in the middle, with 

 cuneate ends. L. 0,07 5 to 0,095; B. 0,o23 to 0,03 mm. Axial area very narrow. Central area 

 large, quadrate, dilated to broad lateral areas on both sides of the median line. Striae 7 to 8 in 

 0,01 mm. smooth, almost parallel. — Nav. arnica Cl. a. Grun. in Cl. N. R. D. p. 12 PL III f. 37. 



Marine: Tahiti! 



C. arnica is remarkable by the broad lateral areas, which are also very much developped in 

 the following two species. These areas occupy the place of the longitudinal lines of the other 

 species of this genus. 



64. C. quadriseriata Cl. a. Grun. (1881). — V. broad, hexagonal, with parallel margins 

 and large, cuneate ends. Median line with small terminal fissures and incrassate central nodule. 

 L. 0,09 to 0,16; B. 0,035 to 0,047 mm. Axial area narrow. Central area large, orbicular. Striae 

 7 to 8 in 0,01 mm., slightly radiate at the ends, elsewhere parallel, smooth. Longitudinal areas 

 broad, linear, attenuated towards the ends. — Nav. quadriseriata Cl. N. R. D. p. 12 PI. Ill f. 32. 

 Nav. duplex Pant. Ill PL XLII f. 579 (1893). 



Marine: Barcelona! Balearic Islands! Gillf of Naples! Levant (Grove Coll.)! 



65. C? kryophila Cl. (1883). — V. elliptic-lanceolate, with cuneate or obtuse ends. 

 L. 0,05 to 0,08; B. 0,oi8 to 0,04 mm. Axial area narrow. Central area small, orbicular, dilated 

 on both sides of the median line to large, lunate lateral areas, on which, faint traces of the striae 



