80 P. T. CLEVE, SYNOPSIS OK TIIK NAVlCiri,()lI) DIATOMS. 



^, I Valvij without ocelli '•>• 



'■*• i - with - 76. 



„r J Furrows narrow L>. dabnatica Ghun, 



'■' I — broad D. Vesjm Cl. 



_ . I Ocelli in a marginal band D. Crahro Eiiii. 



1 — rows alternat.ing witli tlie cost;e 77. 



..{ 



Furrows broad D- ycmmatula Geus. 



— 'narrow 78. 



Costaj 3 to 4 in O.oi mm D. vayaUmda Beun. 



— .') to G — D. lesinensis Grun. 



— 7 — D. prisen A. S. 



D. Hudsonis Grun. (1892). — V. hyaliiie, elliptieal, with more or le.ss ronnded end.<. L. 

 0,036 to 0,05; B. 0,012 to 0,02 mm. Central nodule quadrate, its liorns slightly divergent in the 

 middle. Furrows forming a small, rhomboid, not striate, space around tlie central nodule. Parts 

 outside the furrows striate. Strise fine, 24 to 25 in 0,oi mm. slightlj- radiate at the ends, finel}- 

 punctate; puncta forming obliquely decussating rows. — Xancnla {Biploncis?) Hudsonis (GRrx.) 

 Cl. in Diatomiste I p. 77 Pl. XII f. 8. 



Braekish water: Hudson River! 



This little form is very remarkable and not elo.sely connected witli an}- other known species. 

 It seems to be most nearly related to D. Iiyalinu, but there are considerable differences. 



1. D.? biociilata Grin. (1881). — V. elliptical, with ronnded ends. L. 0,02 to (),(i.ii;; B. 

 0,i)i:i to 0,01.') mm. Central nodule elongated; its horns close to the median line. Central pore.'^ 

 distant, incrassate. Furrows broader than half of the breadth of the val ve. Stri;e 17 to 22 in 

 0,01 mm. not distinctl_y punctate, continued across the furrows to the median line, slightly radiate 

 throughout. — Nav. Uoctdata Grun. A. S. Atl. LXX f. 9, 10, 11, VII f. 49? 



Marine: Balearic Islands! Adriatic! Java! Port Jackson! Galapagos Islands! 



Var. rittata Cl. — L. 0,04; B. 0,oi.t mm. Central nodnle verv narrow; central pores distant. 

 Furrow separated from the exteriör part of the valve by a linear. bi^nad Ijand. Strife 17 in o.iu 

 mm., on the furrows punctate. — Pl. I f. 15. 



Marine: Ce3'lon! 



The exact place of this .species is ditJicult to decide. Tlie iiicrassated central pores recall 

 those of Nar. forcipata, but nevertheless I believe it to be a Diploneis, akin to D. Jn/alina. 



2. D. iiiscripta Cl. N. Sp. — V. lanceolate, subacute, coiivex. L. O.oer); B. O.oi: mm. 

 Central nodule small; its horns close to the median line. Central pores approximate, incrassate. 

 Furrows as broad as half of the valve. StritE 10 in 0,oi mm. continued across the furrows. not 

 distinctly punctate, parallel, very slightly radiate in the ends. — Pl. I f 17. 



Marine: Gulf of Naples! China! 



This species seems to connect the genus Ci/nudoncis. to which it has sonie resemblance, with 

 the forms of the gvoup of D. nifesrens. 



3. D. hyalina Donk. (1861). — V. hyaline, thin, elliptical. L. 0,04 5 to 0,o7g; B. 0,oi4 to 

 0,0 2 6 mm. Central nodule somewhat elongated; its horns slightly divergent in the middle. Furrows 

 much broader than half of the breadth of the valve. Striit- 22 in O.m mm., distinct outside, fainter 

 in the furrows, fading away towards the horns of the median line. — Nar. luialina DoxK. .M. J. I 

 p. 10 Pl. I f. 6. B. D. p. 5 Pl. I f. 1. A. S. Atl. LXX f. 1-5. 



Marine: Finmark! North Sea! 



Var. of D. Crahro. 



