KONGL. SV. VRT. AKADEMIENS IIANDLINOAR. P.AND 26. N:() 2. 1,37 



3. N. Riojfle Cl. (18S1). — V. elliptical, with rounded ends. L. 0,og to 0,o7; B. 0,o23 

 to 0,024 mm. Median liiie in a tliick silicious rib, eombining the large central nodiile witli 

 the thick terminal nodnlea. Terminal lissnres slightly cnrved. Axial and central area nnited 

 in a linear space vevy slightly dilated in tlie middle. 8triii' 17 (iniddle) to 19 (ends) in O.oi mm., 

 radiate thronghont, indistinctly pnnetate, crossed by a shallow. longitndinal depression. — Cl. D. 

 fl-. G-rönl. and Argentina p. 12' Pl. XVI f. 2. 



Fresli water: Argentina (Sierra Faraatina)! 



4. N. Biicillniu Eiib. (1S43). — V. linear with rounded ends. L. 0,o.35 to 0,o.'i5; B. 0,ni to 

 0,01!) mm. Median line in a thick siliceous rib. Axial area iiarrow slightly enlarged aronnd the 

 central iiodule and expanded at the ends on each side to the full width of the valve. Striaä 14 

 (m.iddle) to 20 (ends) very slightly radiate. — Ehb. Am. Pl. IV: r,, f. 8. Grun. A. D. p. 44 Pl. II 

 f. 50. V. H. Syn. p. 10.5 Pl. XIII f. 8. Ströse Kliecken f. 8. K Uvissima Donk. B. D. p. 28 

 Pl. V f . 2 1871? 



Fresh water: Sweden (Skåne)! Finland! Siberia, Month of Jenissey (Grun.), North Anstralia! 

 New Zealand! 



Var.? mexicana Gbun. (1880). — V. gibbous in the middle. L. 0,0.-); B. 0,oi mm. Terminal 

 nodules larger; area abruptly dilated around the central nodule. Strite 18 in 0,oi mm., closer at 

 the ends, in the middle frequently alternately longer and shorter. — Grun. A. D. p. 44. 



Fresh water: Mexico, fossil (Grnn.). 



Var. Gregoryann Grun. (1880). — V. slightly constricted in the middle. — N. Bacilhmi 

 Greg. M. J. IV, Pl. I f. 4 (1856). X. hac. var. Greri. Grun. A. _D. p. 44. 



Fresh water: Loch Leven, Scotland Greg. 



Var. minor V. H. (1885). — V. half as large as the typical form. Strite 16 (middle) to 20 

 (ends) in 0,oi mm. — V. H. Syn. p. 105 Pl. XIII f. 10. 



Fresh water: Belgium (V. H.). 



Var. lepifla Greg. (1856). — V. elliptical with ronnded ends. L. O.oa to 0, 02.^; B. 0, 01 ram. 

 Axial area indistinct, central small. Stricp 17 (middle) to 26 (ends) in 0,oi mm., slightl}' radiate 

 throughout. — N. lepida Greg. M. J. IV Pl. I f. 25. V. H. Syn. Pl. XIII f. 12. Icon. n. Pl. V f. 14. 



Fresh water: Sweden (Hernösand foss.)! Finland (Abo)! Scotland (V. H. T.). Argentina 

 (Sierra Famatina)! 



5. N. trinotata Pant. (1893). — V. linear, with broad, rounded ends. L. 0,o5 6; B. 0,oi4 

 mm. Axial area narrow, slightly dilated in the middle, where is an unilateral stigma. Near the 

 ends of the median lines is also an elongated stigma, placed on contrary sides of the median line. 

 Strise 21, somewhat radiate in the middle, else parallel. — Pant. III Pl. IX f. 152. 



Habitat? »Köpecz^ (Pant.). 



6. N. Pseiido-bacilluni Grun. (1880). — V. linear-elliptical, with rounded ends. L. O.osri 

 to 0,045; B. 0,01 to 0,01.') rara. Terminal nodules with two lateral expansions. Axial area narrow, 

 central area small, rounded. Stria; in the middle 13 (Grun. 21 V. H.) in 0, 01 ram. at the ends 20 

 (Grun. 24 V. H.) in 0, 01 nini.; radiate throughout, very finely punctate. — N. Irevissima Kutz. 

 Bac. p. 96 Pl. XXI f. 14 (1844)? V. H. Syn. Pl. XIII f. 13? N. leptogovf/yln Ehb. p. p.? according 

 to Grun. N. Granum Schum. P. D. II N. p. 58 Pl. II f. 46? according to Grnn. N. lepvissima 

 and N. Fseudo-hac. Grun. A. D. p. 45 Pl. II f. 52 1880. N. Pseudn-har. V. H. Syn. p. 106 Pl. 

 XIII f. 9. iV. Bacillum var. (i Ströse Kliecken f. 9? 



Fresh water: Sweden (Borås)! Finland! Belgium (V. H.), .Java, foss.! Japan! New Zealand! 

 Australian Alps! Canada, foss.! 



This species described and figured by Grunow in A. D. was at first believed by him to be 

 N. Icevissivia Kutz. But as this name may denote sonie form of N. Silicula Grunow proposed the 



K. Vet. Akail. Handl. Band 20. \:o 2. 18 



