KONGL. SV. VET. AKADEMIENS HANDLINGaR. BAND 26. N:0 2. 129 



4. N. Haradaae Pant. (1893). — V. broadly elliptical, with broad, rounded ends. L. 0,025 ; 

 B. 0,018 mm. Axial area indistinct. Central area large, somewhat transverse, half as broad as 

 the valve. Striee 20 in 0,oi mm. radiate throughout. — Pant. Ill PI. VI f. 100. 



Habitat? »Sentenai» (Pant.). 



5. N. depressa Cl. (1891). — V. elliptical, with rostrate ends. L. 0,022; B. 0,oo9 mm. 

 Surface of the valve depressed between the margin and the longitudinal and transverse area. 

 Central area about V3 of the breadth of the valve. Striae 27 in 0,oi mm., more distant (about 24 

 in 0,01 mm.) in the middle, slightly radiate, especially near the ends. — Cl. D. of Finl. p. 35 

 PI. II f. 4. 



Fresh water: Sweden, Areskutan in Jamtland! Wernamo, fossil! Finland (Imandrian Lap- 

 land, Suomenniemi, fossil)! 



6. N. binodis Ehb. (1840). — V. strongly constricted in the middle, with rostrate-capitate 

 ends. L. 0,025; B. 0,oo8 mm. Axial area indistinct. Central area small. Striae about 30 in 0,oi 

 mm., sligthly radiate. — Ehb. Ber. 1840 p. 18. W. Sm. B. D. I p. 53 PI. XVH f. 159. Grun. 

 Verh. 1860 p. 551 PL II f. 42. Donk. B. D. p. 38 PI. VI f. 3. V. H. Syn. p. 108, Suppl. PI. B. f. 33. 



Fresh water: England (Sm.), Belgium (V. H.), Switzerland! Japan! 



7. N. (Dickieia) ulvacea Bbrkl. (1844). — V. linear-elliptical, with rounded ends. L. 0,025 

 to 0,035; B. 0,008 to 0,012 mm. Axial area indistinct. Central area a narrow, transverse fascia 

 furcate at the margin. Striae 16 in 0,oi mm., slightly radiate at the ends. Frustules in leaf-like, 

 flat and stipitate gelatinous mass, in length about 1 to 5 cm. — Dickieia ulv. Bbrkl. in Kiitz. 

 Bac. p. 119. V. H. Syn. PI. XVI f. 10. 



Marine: Scotland (Dickie), Ireland (O'Meara), Balearic Islands! 



8. N. asymmetrlca Pant. (1893). — V. narrow elliptical, obtuse. L. 0,025; B. 0,oi mm. 

 Central area a broad fascia, reaching the margins, where is, unilaterally, in the middle of the area 

 a single stria. Striae radiate, 19 in 0,oi mm. — Pant. Ill PI. VII f. 110. 



Habitat? »Sentenai» (Pant.). 



9. N. mntica KtiTZ (1844). — V. of variable shape, elliptic-lanceolate, frequently with un- 

 dulated margins. L. 0,oi3 to 0,033; B. 0,oo7 to 0,oii mm. Axial area narrow. Central area 

 large, transversely dilated, with an isolated punctum on one side of the central nodule. Striae 18 

 to 20 in 0,01 mm. radiate at the ends, distinctly punctate. A few of the median striae shorter 

 than the rest. — KtJTZ Bac. p. 93 PL III f. 32 (according to Arnott). GrRUN. A. D. p. 40. 



'^ Forma Cohnii- HilsE (1860). — V. elliptic-lanceolate, with rounded ends. — Stauron. Cohnii 

 HiLSB Beitr. p. 83. N. mutica v. Coh. V. H. Syn. p. 95 PL X f. 17. Stauron. polymorpha Lagst. 

 Spitsb. D. p. 39 PL I f. 12. 



' Brackish water: Spitsbergen! Belgium (V. H.), Bengal! Daintree River, Australia! Lost 

 Spring' Ranch, Calif. ! 



Forma Goppertiana Bleisch (1861). — V. lanceolate. — Stauroneis Semen Ehb. M. G. XXXVIII 

 A 20 f 1 (1854)? Stauron. Goppertiana Bleisch Rabh. A. E. N:o 1183 (1861). Nav. mutica 

 Grun. Verh. 1860 p. 538 PL V f. 16. Stauron. Uohnii Schum. Tatra p. 78 PL IV f. 61. N. mut. 

 V. Goppertiana V. H. Syn. p. 95 PL X f. 18, 19. 



Fresh or brackish water: Belgium (V. H.), Nova Scotia! West Indies! Ecuador! 



Forma producta Grun. (1880). — V. lanceolate, with broad, truncate ends. — Grun. A. D. p. 41. 



Forma ventricosa KtJTZ (1844). — V. inflated, with capitate ends. L. 0,oi6 to 0,022; B. 0,06 

 to 0,08 mm. Striae 17 in 0,oi mm. — Stauron. ventric. KtJTZ Bac. p. 105 PL XXX f 27. Greg. 

 M. J. IV PL I f. 10 (1856). Nav. (St.) vent. V. H. Syn. p. 96 PL IV f. 1 b. 



Brackish water: Argentina! 



K. Sv. Vet. Akad. Hand. Band 26. N:o g. 17 



