192 r. T. OLEVE, SYNOPSIS OF THE NAVICULOII) DIATOMS. - 



Asyvimctrica I forms. 



Var. californira Cl. — V. linear-lanceolate, obtuse. L. 0,17 to 0,22; B. (),o:i to 0,o:U) inia. 

 Axial area linear, unilateral. Alveoli close, disposed in irregular, longitudinal rows, and slightly 

 radiate, transverse rows, fi to 7 in 0,oi mm. 



Marine, fossil: Japan (Brun Coll.)! San Pedro (Kinker Coll.)! S:ta Monica Cal. (Deby Coll.)! 



Var. derasa Cl. — V. linear, obtuse. L. 0,22; B. 0,023 mm. Axial area broad and irregu- 

 lar, unilateral, ('antral area a broad fascia, reaching to the margin. Alveoli close, forming 

 oblique rows and slightly radiate, at the ends parallel, rows, 7 in 0,01 jnm. 



Marine: Madagascar (Kinker Coll.)! 



Var. intermedia Griin. (1876). — V. narrow lanceolate to elliptic-linear. L. 0,i to 0,19; 

 B. 0,019 to 0,026 mm. Axial area narrow, unilateral. Alveoli forming longitudinal or oblique 

 rows, and transverse, slightly radiate rows, 7 to 9 in 0,oi mm. — Nav. asjiera var. interm. (tRun. 



A. S. Atl. XLVIII f. 14. Franz Josephs Land 1). PI. I f. 20. Nar. aspera rar. hiou/ariea Pant. 

 IT p. 42 PL X f. 180 (1889). 



Marine: Greenland! Spitzbergen! Franz Josephs Land ((irrun.), Finmark! Sea of Kara! Cape 

 Deshneff! North Sea! Fossil: St. Peter, Hungary! Brtinn! Sendai, Japan! 



Var. ohlonga Bail (1854). — V. linear, with subcuneate ends, and frecjuently with a median 

 gibbosity. L. 0,17 to 0,22; B. 0,o4 to 0,o5 mm. Axial area narrow, linear, unilateral. Alveoli 

 close, in oblique and transverse rows, the latter slightly radiate, 7 to 10 in 0,01 mm. — Stauroptera 

 ohlonga Bail Smiths. Contr. 1854 p. 10 f. 17. St. ohlonga? A. S. Atl. PI. XLVIII f. 10. Stanro. 

 tieis ohlonga Castr. Voy. Challenger p. 24 PI. XX f. 7 to 11. 



Marine: Sydney! Kerguelens Land! South America, fossil! 



Var. rhomhica Cl. — V. rhomboid. L. 0,12; B. 0,o.5.') mm. Ends acute. Median line ex- 

 centric. Axial area linear, unilateral. Central area large. Costa? near the margin transverse, 9 

 in 0,01 mm. Alveoli arranged in oblique rows, crossing each others in an angle of about 80°, (5 

 in (>,(»i mm. 



Marine: Galapagos Island! 



Var. pHrohliqua Cl. — V. linear, gradually tapering towards the obtuse ends. L. 0, ir,8; 



B. 0,02 mm. Median line very excentric. Axial area indistinct. Alveoli an'anged in ol)li(je and 

 transverse rows, the latter 8 to 9 in 0,oi m. m. — PI. Ill f. 37. 



Marine: Macassar Straits (Grove Coll.)! 



Var. Amphora Brun (1891). — V. strongly asymmetrical. L. 0,09 to 0,i4 mm. Axial area 

 irregular, unilateral. Central area small. Alveoli arranged in oblique and transverse rows, the 

 latter 6 in 0,oi mm. — h'av. Amphora Brun De especes n. p. 32 PI. XV f. 8. 



Marine: Port au Prince and King Georgs Sound (Brun). 



Var. Schmidtiana Grun. (1876). — Lanceolate, somewhat gibbous in the middle, obtuse. 

 L. 0,08 to 0,11; B. about 0,0 17 mm. Axial area linear, unilateral. Alveoli distant, disposed in 2 

 to 3 longitudinal rows and in transverse rows, 9 to 12 in 0,oi mm. - JSar. Srhm. A. S. Atl. 

 XLVIII f. 19, 20. 



Marine: Campeachy Bay! Galapagos Islands 1 



2. T.(?) tliniidula Grun. (1860). — V. gibbous in the middle and with broad, truncate ends. 

 L. 0,025; B. 0,011 mm. Axial area indistinct; central area a broad fascia, reaching the margin, 

 where it is dilated. Rows of alveoli radiate, 13 in 0,01 mm. — Staiironcis tmuid. (tRun. Verb. 

 1860 p. 56(J PI. VI f. 10. 



Marine: Red Sea (Grun.). 



I have not seen this form, wliicli, to judge from Grunow's description, seems to belong to 

 Trachyneis. 



3. T. Clepsydra Donk. (1861). — Frustule rectangular, constricted in the middle. V. convex, 

 linear lanceolate, with obtuse or subtruncate ends. L. 0,i 1 to O.1.3; B. 0,02 mm. Median line 



