KONOL. SV, VKT. AKADEMIENS HANDLINGAK. HAND 26. N:() 2. 129 



4. N. Harudase Pant. (1893). — V. broadly elliptical, with broad, rounded ends. L. 0,02.'); 

 B. 0,0 18 mm. Axial area indistinct. Central area large, .somewhat transver.se, half as broad aa 

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



Habitat? »Sentenai» (Pant.). 



5. N. (lepressa 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 '/a of the breadth of the valve. Stria' 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 

 PL 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,o2r); B. 0,ou8 mm. Axial area indistinct. Central area small. Strite about 30 in 0,oi 

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

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



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



7. N. (Dickieia) nlvacea Berkl. (1844). — V. linear-elliptical, with rounded ends. L. 0,02.5 

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

 furcate at the margin. Strite 16 in 0,oi mm., slightly radiate at the ends. Fi'ustules in leaf-like, 

 flat and stipitate gelatinous mass, in length about 1 to 5 cm. — Dickieia nlv. Berkl. in Kutz. 

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



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



8. N. asymmetrica 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. Stria; radiate, 19 in 0,oi mm. — Pant. Ill PL VII f. 110. 



Habitat? »Sentenai> (Pant.). 



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

 dulated margins. L. 0,oi3 to Ojos.-i; B. 0,oo7 to O,oii mm. Axial area narrow. Central area 

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

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

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



Forma Cohnii HiLSE (1860). — V. elliptic-lanceolate, with roimded ends. — Sfanron. Cohnii 

 HiLSE 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 Blelsch (1861). — V. lanceolate. — Stauroneis Semen Ehb. M. G. XXXVIII 

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

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

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



Fresh or brackisli 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 rmtricosa KOtz (1844). — V. inflated, with capitate ends. L. 0,oig to 0,022; B. 0,06 

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

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



Brackish water: Argentina! 



K. Sv. Vet. Akad. llaud. Baud 2G. N:o 2. 17 



