80 V. r. (LRX'I-:, SVXOI'.SIS of THK NAVlCUI.dll) diaioms. 



Valv without otclli 75 



{ 



with — _ th. 



_^ j Furrows narrow D. dalmntica Grun. 



1 — broad D. Veapa Cl. 



I Ocelli in a marginal hand I). Crabro EiiH. 



lo. < 



\ — rows alternating witli the coslie , 77. 



„_ J Furrows broad I>. iicmmatnln Grun. 



\ — narrow iH. 



ICost.ae 3 to 4 in O.oi mm D. vagnhunda Brun. 

 — 5 to () — D. lesine.nsis Grun. 

 — 7 — D. priscd A. S. 



D. Hiulsonis (tRUN. (1892). — V. hyaline, elliptical, with more or less rounded ends. L. 

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

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

 outside the furrows striate. Strite tine, 24 to 25 in 0,oi mm. slightly radiate at the ends, finely 

 pnnetate; puncta forming obliquely decus.sating rows. — Naricnla (Dijiloncis?) Had son is (Gkin.) 

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



Brackish water: Hudson River! 



This little foi'ni is very remarkable and not closely connected with any other known species. 

 It seems to be ntost nearly related to D. /ii/alhui, but there are considerable differences. 



1. D.? bioculata Gtrin. (1881). — V. elliptical, with rounded ends. L. O.02 to 0,030; B. 

 0,0 i:i to 0,0 1;-) mm. Central nodule elongated; its horns close to the median line. Central pores 

 distant, incrassate. Furrows broader than half of the breadth of the valve. Stria- 17 to 22 in 

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

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



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



Var. rittota Cl. — L. 0,o4 ; B. 0,oi5 mm. Central nodule very narrow; central pores distant. 

 Furrow separated from the exterior part of the valve by a linear, l)road band. Stride 17 in 0,01 

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



Marine: Ceylon! 



The exact place of this species is difJicitlt to decide. The incrassated central pores recall 

 those of N(ir. forcipafa, but nevertheless I believe it to be a Diploneis, akin to D. hyalina. 



2. D. inscriptsi Cl. N. Sp. — V. lanceolate, subacute, convex. L. 0,()r,5; B. O.oi: mm. 

 Central nodule small; its horns close to tlie median line. Central pores a])proximatp, incrassate. 

 Furrows as broad as half of the valve. Strisc 10 in 0,oi mm. continued across the fnri'ows, 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 Cymafonr/s, to which it has some resemlilance, with 

 the forms of the group of I), vifcsrois. 



3. D. hyalina Donk. (1861). — V. hyaline, thin, elliptical. L. 0,o4 5 to 0,o:c; B. 0,014 to 

 0,020 mm. Central nodule somewhat elongated; its horns slightly divergent in the middle. Furrows 

 much broader than half of the breadth of the valve. Stria-. 22 in 0,oi mm., distinct outside, faintei' 

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

 p. 10 PI. I f. G. B. D. p. "5 PI. I f. 1. A. S. Atl. LXX f. 1—5. 



Marine: Finmark! North Sea! 



' Var. of D. Crabro. 



