KONGL. SV. VET. AKADEMIENS HANDLINGAU. BAND 26. N:0 2. 137 



3. N. Biojoe Cl. (1881). — V. elliptical, with rounded ends. L. 0,o6 to 0,o7; B. 0,o23 

 to 0,024 mm. Median line in a thick silicious rib, combining the large central nodule with 

 the thick terminal nodules. Terminal fissures slightly curved. Axial and central area lanited 

 in a linear space very slightly dilated in the middle. Striae 17 (middle) to 19 (ends) in 0,oi mm., 

 radiate throughout, indistinctly punctate, crossed by a shallow, longitudinal depression. — Cl. D. 

 fr. Gronl. and Argentina p.. 12 PI. XVI f. 2. 



Fresh water: Argentina (Sierra Famatina)! 



4. N. Bacilliim Ehb. (1843). — V. linear with rounded ends. L. 0,03s to 0,055; B. 0,oi to 

 0,015 mm. Median line in a thick siliceous rib. Axial area narrow slightly enlarged around the 

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

 (middle) to 20 (ends) very slightly radiate. — Ehb. Am. PI. IV: 5, f. 8. Grun. A. D. p. 44 PI. II 

 f. 50. V. H. Syn. p. 105 PI. XIII f. 8. Strose Kliecken f. 8. N. Imvissima Donk. B. D. p. 28 

 PI. V f . 2 1871? 



Fresh water: Sweden (Skane)! Finland! Siberia, Mouth of Jenissey (Grrun.), North Australia! 

 New Zealand! 



Var.? mexicana Grun. (1880). — V. gibbous in the middle. L. 0,05; B. 0,oi mm. Terminal 

 nodules larger; area abruptly dilated around the central nodule. Striae 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 (Grun.). 



Var. Gregoryana Grun. (1880). — V. slightly constricted in the middle. — N. Bacillum 

 Greg. M. J. IV, PL I f . 4 (1856). N. bac. var. Greg. Grun. A. D. p. 44. 



Fresh water: Loch Leven, Scotland Greg. 



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

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



Fresh water: Belgium (V. H.). 



Var. lepida Greg. (1856). — V. elliptical with rounded ends. L. O.oa to 0,025; B. 0,oi mm. 

 Axial area indistinct, central small. Strife 17 (middle) to 26 (ends) in 0,oi mm., slightly 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 (Hernosand foss.)! Finland (Abo)! Scotland (V. H. T.). Argentina 

 (Sierra Famatina)! 



5. N. trinotata Pant. (1893). — V. linear, with broad, rounded ends. L. 0,05 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. 

 Striae 21, somewhat radiate in the middle, else parallel. — Pant. Ill PL IX f. 152. . 



Habitat? »Kopecz» (Pant.). 



6. N. Pseudo-bacilluni Grun. (1880). — V. linear-elliptical, with rounded ends. L. 0,035 

 to 0,045; B. 0,01 to 0,015 mm. Terminal nodules with two lateral expansions. Axial area narrow, 

 central area small, rounded. Strise in the middle 13 (Grun. 21 V. H.) in 0,oi mm. at the ends 20 

 (Grun. 24 V. H.) in 0,oi mm.; radiate throughout, very finely punctate. — N. Imvissima Kutz. 

 Bac. p. 96 PL XXI f. 14 (1844)? V. H. Syn. PL XIII f. 13? N. leptogongyla Ehb. p. p.? according 

 to Grun. N. Granum Schum. P. D. II N. p. 58 PL II f. 46? according to Grun. N. Imvissima 

 and N. Pseudo-bac. Grun. A. D. p. 45 PL II f. 52 1880. N. Pseudo-bac. V. H. Syn. p. 106 PL 

 XIII f. 9. N. Bacillum var. /J Strose Kliecken f. 9? 



Fresh water: Sweden (Boras)! 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. leevissima KtJTZ. But as this name may denote some form of -A". Silicula Grunow proposed the 



K. Vet. Akad. Haudl. Band 26. N:o 2. 18 



