KONGL. SV. VET. AKADEMIENS HANDLINGAR. RAND 26. N:0 2. .53 



11. C? elongjitiila Pant. (1889). — V. linear, witli lounded ends. L. 0,021; B. 0,no8 mm. 

 Axial area indistinct; central small, orbicular. Strise 20 in 0, 01 mm. parallel. Longitudinal lines? 

 — Nav. elongatula Pant. II p. 45 Pl. III f. 40. 



Brackish water: Hnngary, foss. (Pant.). 



The fig. of this species in Pantocseks work is not sufficient for determining tke systematical 

 place of this form, which seems to be related to C. SUicula. I have fonnd in the deposit of Gyon- 

 gyös Påta (Hungary) a form, which agrees Avith N. dongatula in outline and in the niTmber of 

 strife, but is 0,0 4 mm. in length. In this form the striEe on both sides of the central nodule are 

 interrnpted by a short Innate, longitudinal line. 



12. C. Schunianniana GtRUN. (1880). — V. strongly inflated in the middle, with rounded 

 obtuse ends. L. 0, 037 to 0,o.-); B. 0,oo'.) to 0, 01.3 mm. Axial area indistinct or narrow. Central 

 area lanceolate with a Innate marking on each side of the central nodule. Strice. 17 in 0, 01 mm., 

 radiate at the ends (very finely punctate?). Longitudinal lines indistinct. — Nav. Trochus Schum. 

 P. D. I p. 189 f. 52. Greg. M. J. IV Pl. I f. 2 (1856). Nav. Schmnanniana Grun. V. H. Syn. 

 p. 99 Pl. XI f. 21. 



Fresh water: Sweden, Ringsjön in Skåne! Ladoga! Königsberg, fossil! 



Var. trinodis Lewis (1861). — V. divided by two constrictions into three segments of equal 

 size. Ends cuneate. L. 0,o34 to 0,042; B. 0,ou mm. StriiE 18 to 20 in 0,oi mm. strongly 

 radiate in the middle, almost parallel in the terminal segments. — Nav. trinodis Lewis Proc. 

 Ac. n. se. Philad. p. 66 Pl. II f. 6 (1861). — Nav. biconsfricta Grun. Casp. S. Alg. p. 15 Pl. III 

 f. 6 (1878). 



Fresh and brackish water: Caspian Sea (Grun.) N. America, Hudson River! Delaware! Da- 

 kota! Lake Pistaku, Illin.! Löst spring Ranch, Calif. ! 



13. C? bodosensis Pant. (1893). — V. trochiform, obtuse. L. 0,077; B. 0,02 mm. Axial 

 area lanceolate, dilated in the middle to a transverse fascia, and with an elongated marking on both 

 sides of the central nodule. Strite 17 in 0,oi mm. almost parallel. — N^av. bodos. Pant. III 



Pl. ni f. 35. 



Habitat?: Bodos» (Pant.). 



Var. Uerihaudi Per. (1893). — V. in L. 0,07 to 0,oy; B. 0,ö16 mm. biconstricted. Strise 17 

 in 0,01 mm. — Nav. Her. Perag. in Hérib. D. dMuvergne p. 112 Pl. IV f. 8. 

 Fresh water: Puy de Döme. Varennes (Brun CoU.)! 



14. C. alpestris Grun. (1860). — V. linear, slightly gibbous in the middle, with rounded 

 or subcuneate ends. L. 0,o6 to 0,o76; B. 0,oo6 to 0,ooy mm. Axial and central area united in 

 a narrow lanceolate space, having on each side of the central nodule a Innate marking. Stria3 20 

 in 0,0 1 mm. nearly parallel; slightly divergent at the ends. Longitudinal lines distinct, submar- 

 ginal. - Nav. alpestris Grun. Verh. 1860 p. 545 Pl. V f. 4. V. H. Syn. Pl. XII f. 30. 



Fresh water, alpine regions: Swedens Lake Mälaren (in postglacial mud!), Austrian alps, 

 (Grun.), Savoy! 



Nav. alpestris var. tatrica Gutw. p. 20 Pl. I f. 17 — is no var. of C. alpestris and appears 

 to be a Frustulia or Neidium, impossible to decide from the figures. 



15. C. nubicola Grun. (1880). — V. slightly triundulated. Central area dilated transversely 

 to a fascia, with lunate markings on both sides of the central nodule. — Nav. nubicola Grun. 

 in V. H. Syn. Index to Pl. XII f. 30. 



Fresh water: Turkestan (Grun.). 



16. C. Kaiuitzii Pant. (1893). — V. elongated, gibbous in the middle, with broad, obtuse 

 ends. L. 0. los; B. 0,02 mm. Axial area broad, linear-lanceolate, with an elongated marking on 



