KONGL. SV. VET. AKADEMIBNS HANDLINGAR. BAND 26. N:0 2. 53 



11. C? elongatnla Pant. (1889). — V. linear, with rounded ends. L. 0,o2i; B. 0,oo8 mm. 

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

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



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



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

 place of this form, which seems to be related to C. Silicula. I have found in the deposit of Gryon- 

 gyos Pata (Hungary) a form, which agrees with N. elongatula in outline and in the number of 

 striae, but is 0,o4 mm. in length. In this form the striee on both sides of the central nodule are 

 interrupted by a short lunate, longitudinal line. 



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

 obtuse ends. L. 0,037 to O.os; B. 0,oo9 to 0,oi3 mm. Axial area indistinct or narrow. Central 

 area lanceolate with a lunate marking on each side of the central nodule. Striae 17 in 0,oi 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 PI. I f . 2 (1856). Nav. Schumanniana Grun. V. H. Syn. 

 p. 99 PL XI f. 21. 



Fresh water: Sweden, KingsjSn in Skane! Ladoga! Konigsberg, 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,oii mm. Striae 18 to 20 in 0,oi mm. strongly 

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

 Ac. n. sc. Philad. p. 66 PL II f. 6 (1861). — Nav. hiconstricta Grun. Gasp. S. Alg. p. 15 PL HI 

 f. 6 (1878). 



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

 kota! Lake Pistaku, lUin. ! Lost spring Ranch, Calif.! 



13. C? bodosensis Pant. (1893). — V. trochiform, obtuse. L. 0,o7 7; 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. Striae 17 in 0,oi mm. almost parallel. — Nav. hodos. Pant. Ill 

 PL ni f. 35. 



Habitat?: »Bodos» (Pant.). 



Var. Heribaudi Per. (1893). — V. in L. 0,o7 to 0,09; B. 0,oi6 mm. biconstricted. Striae 17 

 in 0,01 mm. — Nav. Her. Perag. in Herib. D. d'Auvergne p. 112 PL IV f. 8. 

 Fresh water: Puy de Dome. Varennes (Brun Coll.)! 



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

 or subcuneate ends. L. 0,06 to 0,076; B. 0,oo6 to 0,oo9 mm. Axial and central area united in 

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

 in 0,01 mm. nearly parallel; slightly divergent at the ends. Longitudinal lines distinct, submar- 

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



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

 (Grun.), Savoy! 



Nav. alpestris var. tatrica GuTW. p. 20 PL If. 17 — is no var. of C. alpestris and appears 

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



15. C. nuMcola 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. Kainitzii Pant. (1893). — V. elongated, gibbous in the middle, with broad, obtuse 

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



