KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 27. N:0 3. 35 



Var. maxima Cl. — V. less convex, lanceolate, acute. L. 0,13; B. 0,03 mm. Strise 6,5 in 

 0,01 mm. almost parall el, composed of about 7 elongated puncta, lineate, lineolBe about 27 in 0,oi mm. 



Marine: Gnlf of Naples (Brun's Coll.)! 



Var.? Peragalli Brun (1891). — V. rhomboidal, acute; the axial part forming a distinct keel 

 especially towards the ends. L. 0,o8 to 0,ii; B. (),025 to 0,o3o mm. Strise 7 in 0,oi mm, slightly 

 radiate, composed of about 7 elongated puncta, crossed by fine lineolse, about 27 in 0,oi mm. — 

 N. Feragalli Brun D. espéces n. p. 37 Pl. XVI f 12. 



Marine: Gulf of Naples! Athens (Brun). 



90. N. (Alloioneis) Monodon Brun (1891). — V. very convex, narrow, rhombic-lanceolate, 

 subacute. L. 0,06 to 0, 09; B. O.oi 1 mm. Central nodule strong, elevated with a pore in the 

 middle. Terminal nodules distant. Axial area asymmetrical narrow, slightly dilated around the 

 central nodule. Striifi 6 to 8 in 0,oi mm. crossed by undulating, narrow, longitudinal areas. V. 

 in zonal view broad, slightly constricted in the middle, with obliquely truncate ends. Central 

 nodule forming a conical projection, perforated by a tube. Strise composed of elongated puncta. 

 — Diat. espéces n. p. 36 Pl. XVI f. 8. 



Marine: Japan (Brun)! 



This is one of the most remarkable naviculoid diatoms, diverging from all other known 

 forms by its central nodule, forming a conical, perforated projection on the outside of the valve. 



91. N. distans W. Sm. (1853). — V. lanceolate, gradually tapering from the middle to the 

 obtuse ends. L. 0,09 to 0, 13; B. 0,oi7 to 0, 02 mm. Axial area gradually dilated towards the 

 middle, where it expands to a large, rounded quadrate space. Strise 5 to 6 in 0,oi mm., radiate 

 throughout, strongly lineate; lineolse 21 in 0, 01 mm. — Finn. distans "W. Sm. B. D. I p. 56 

 Pl. XVIII f. 169. K distans A. S. Atl. XLVI f. 11 to 14. N. S. D. II f. 38 (without name). 

 V. H. Syn. p. 87 Suppl., Pl. A f. 18. N. dist. r. borealis Grun. A. D. p. 38 Pl. II f. 42. 



Marine: Frans Josefs Land (Grrun.), Spitsbergen! Finmark! Greenland! North Sea! 

 N. distans seems to belong to the Arctic Sea and Northern Atlantic. I have not seen 

 typical specimens from other seas. 



92. N. subalata Grun. (1880). — V. lanceolate, obtuse. L. 0,o8; B. 0,02 mm. Median line 

 with approximate central pores and distant terminal nodules. Axial area linear distinct. Central 

 area large, somewhat transverse. Strise 6 in 0, 01 mm. radiate throughout, transversely lineate; 

 lineolfe 22 in 0,oi mm. The strise in the middle do not reach the margin, so that the valve 

 seems there to be bordered by a hyaline rim. — A. D. p. 38. Icon. n. Pl. I f. 32. 



Marine: Seychelles (Van Heurck Coll.)! 



An original sketch by Grunow agrees perfectly with the specimen in Van Heurck Collec- 

 tion, which has distinctly lineate strise. According to Grunow they are smooth. 



93. N. salra A. S. (1876). — V. elliptic-lanceolate, sometimes with slightly triundulated 

 margins and subrostrate ends. L. O, oss to 0,o6; B. 0,02 to 0,022 mm. Median pores approximate; 

 terminal nodules distant. Axial area narrow, linear. Central area large, quadrate. Strise 8 in 

 0,01 mm. radiate throughout. — Atl. XLVI f. 23. 



Marine: Balearic Islands! Campeachy Bay (Atl.), Florida! 



94. N. opima Grun. (1867). — V. elliptic-lanceolate, with rounded, obtuse ends. L. 0,0 6 

 to 0,11; B. 0,017 to 0,025 mm. Central pores approximate; terminal fissures almost straight, 

 large, at some distance from the ends of the valve. Axial area broad, linear. Central area large, 

 orbicular. Strise 6 to 8 in 0,oi mm., more distant in the middle; strongly radiate throughout, 

 lineate; lineolse 24 in 0,oi mm. — N. fortis var.? opima Grun. Novara p. 100 Pl. 1 A f. 13. N. 

 opima A. S. Atl. XLVI f. 24, 25, 26. N. fortis A. S. Atl. XLVI f. 19, 20, 21, 22. 



Marine: Greenland! Davis Straits! Grip in Norway! Baltic (Atl.), Barcelona! 



