96 p. T. CLBVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 



Var. asymmttrica Cl. (1883). — V. linear, with subcuneate ends. L, 0,08; B. 0,oi8 mm. 

 Axial area narrow, unilateral. Striae 8 in 0,oi mm. — Nav. Finn. var. asym. Cl. Vega p. 463. 



Marine: Cape Wankarema! 



Var. subproduda Grun. (1880). — V. linear, with somewhat rostrate ends. B. 0,oi mm. 

 Strise 12 in 0,oi mm. — Nav. Finn. var. suhp. Geun. A. D. p. 28. 



Brackish water: Baltic (Grun.). 



Var. amphiglottis Gkun. (1884). — V. linear, with protracted ends. L. 0,ii5 mm. — Nav. 

 Stuxhergii var. amphigl. Grun. Franz Josefs Land D. p. 104. 



Brackish water: North Siberia (Grun.). 



B. Forms ivith subelliptical to sublanceolate valves. 



Var. Stuxbergii Cl. (1880). — V. lanceolate, with broad, rounded or subcuneate ends. L. 

 0,059 to 0,1 ; B. 0,016 to 0,oi7 mm. Strise 10 to 12 in 0,oi mm. (finely punctate according to 

 Grunow). — Nav. Stuxbergii Cl. A. D. p. 13 PI. I f. 15. 



Marine: Sea of Kara! Cape Wankarema! 



Var. leptostauron Grun. (1884). — V. elliptic-linear. L. 0,04 to 0,o57; B. 0,oi2 to 0,oi3 

 mm. Central fascia with three indistinct striae. Strise 11 in 0,oi mm. — Nav. Stuxbergii var. 

 leptost. Grun. F. Jos. Land D. p. 103 PI. 1 f. 32. 



Marine: Franz Josefs Land (Grun.). 



Var. subcontinua Grun. (1884). — V. elliptic. L. 0,o4; B. 0,oi4 mm. Central fascia with 

 one or two indistinct striae. — Nav. Stuxbergii var. subc. .Grun.^ Fr. Jos. Land D. p. 103 PL I f. 33. 



Marine: Franz Josefs Land (Grun.). 



Var. Theelii Cl. (1880). — V. lanceolate, with rostrate, obtuse ends. L. 0,055; B. 0,oi7 mm. 

 Striae slightly radiate, 10 to 12 in 0,oi mm. — Nav. Theelii Cl. A. D. p. 13 PI. I f. 22. 



Marine: Kara! Cape DeschnefF. 



C. Forms constricted in the middle. 



Var. flumincnsis Grun. (1860). — V. linear, slightly constricted in the middle, with broad, 

 rounded extremities. L. 0,04?; B. 0,oo8 mm. Striae 11 in 0,oi mm. — Nav. fluminensis Grun. 

 Verb. 1860 p. 520 PL III f. 7. A. D. p. 28. 



Marine: Kara! Adria (Grun.), Ceylon! Seychelles! 



Var. kerguelensis Grun. (1880). — V. linear, constricted in the middle. L. 0,057; B. 0,oo9 

 (middle) to 0,oi2 (end) mm. Striae 8,5 to 10 in 0,oi mm. — Nav. fluminensis var. Tterq. Grun. 

 A. D. p. 28. 



Marine: Kerguelens Land! 



Var. minor Grun. (1880). — L. 0,032; B. 0,oo5 (middle) to 0,oo6 (end) mm. Striae 15 in 

 0,01 mm. — Nav. flumin. var. minor Grun. A. D. p. 28 PL I f. 12. 



Marine: Finmark! 



Var. Loczyi Pant. (1889). — V. linear, slightly constricted in the middle, with cuneate ends. 

 L. 0,081 ; B. 0,007 (middle) to 0,oi45 (ends) mm. Striae 17,5 in 0,oi mm. — Nav. Loczyi Pant. II 

 p. 50 PL VI f. 114. 



Marine: Bremia Dept. Hungary (Pantoczek). 



I have not seen original specimens and am therefore uncertain whether this form really 

 belongs to P. quadratarea or whether it is a Caloneis. 



73. P. Claviculus Gnm. (1857). — V. linear, with two constrictions, dividing the valve 

 into three segments, of which the median one is the smallest. L. 0,038 to 0,048; B. in the middle 

 0,006, at the ends 0,oo7 mm. Median line with approximate central pores and distant terminal 

 pores. Axial area indistinct; central area a broad, transverse fascia. Striae parallel, 12 to 13 in 



