KONGL.* 8V. VET. AKADEMIENS HANDLINGAR. BAND 26. N:0 2. 163 



Strise 9 or 11 (middle) to 12 (ends) in 0,oi mm. slightly radiate, especially near the ends, punctate; 

 puncta about 22 in 0,oi mm. — Cocc. lept. Ehb. Am. PL I: 2 f. 30. Gy. leptoc. V. H. Syn. p. 62 

 PL II f. 18, III f. 24 (f. curta) Suppl. A. f. 2 (f. elongata). Cy. hungarica Past. II p. 40 PL I 

 f. 14 (1889)? 



Fresh water: Rostock (foss.), Belgium! Hungary foss. (Pant.)? Mexico, foss.! 



Var. minor Grdn. (1882). — L. 0,026; B. 0,oot mm. — Grun. Foss. D. Osterr. Ung. p. 142 

 PL XXIX f. 32. 



Fresh water: Hungary, fossil (Grun.). 



Var. amiusta Grun. (1882). — L. 0,024 to 0,o4; B. 0,oo5 to 0,oi mm. Strise 12 to 15 in 

 0,01 mm. - Grun. Foss. D. Osterr. Ung. p. 142 PL XXIX f. 33, 34. 



Fresh water: Greenland! Hungary, fossil (Grun.), Geneva! Savoy! 



Var. excisa Pet. (1877). — Ventral margin indented in the middle. — C. turgida var. excisa Pet. 

 Bull. Soc. Bot. de France 1877 PL I f. 2. A. S. Atl. LXXI f. 35. Gkuk. Foss. D. Osterr. Ung. p. 142. 



Fresh water: Marly, near Paris (according to Grunow). 



The most marked characteristic of C. leptoceros is the distinct axial area, which seems to 

 become much reduced in some of the varieties, named by Grunow, especially in the var. excisa 

 which I have placed here on the authority of Grunow. Specimens of that var. from Marly (CI. M. 

 I). N:p 195) agree in my opinion with C. tumidula Grun. 



The following forms, found in a fossil state in Hungary and described by Pantocsbk seem 

 to be nearly akin to C. leptoceros. 



C. havnensis Pant. (II p. 40 PL XI f. 186). — L. 0,025; B. 0,oo75 mm. Strise 15 in 0,oi mm. 



C. Neupaueri Pant. (II p. 40 PL Xlf. 187). — L. 0,027; B. 0,0095 mm. Striee 15 in 0,oi mm. 



Specimens from Gyongios-Pata, which I have examined, are scarcely distinguishable from 

 C. leptoceros in Van Heurck's Types. 



15. C. aiistriaca Grun. (1875). — V. asymmetrical; with arcuate dorsal margin and slightly 

 convex ventral margin. Ends obtuse and rounded. L. 0,o45 to 0,068; B. 0,oi2 to 0,oi7 mm_ 

 Median line somewhat excentric, nearly straight, broad (oblique). Axial area distinct, linear, not 

 widened in the middle. Strise 11 or 13 (dorsal) to 13 or 14 (ventral) in 0,oi mm., radiate through- 

 out, punctate; puncta about 21 in 0,oi mm. — Grun. in A. S. Atl. IX f. 10, LXXI f. 67 to 69. 



Fresh water: Tyrol (Atl.), Switzerland (St. Gingolf, Engadine)! 



Var. prisca Grun. (1882). — L. 0,o5 to 0,o78; B. 0,oi3 to 0,oi9 mm. Median line slightly 

 arcuate. Area slightly dilated on the dorsal side of the central nodule. Strise 9 (middle) to 11 

 (ends) in 0,oi mm., punctate. Puncta 23 in 0,oi mm. — Grun. Foss. D. Osterr. Ung. p. 143 

 PL XXIX f. 29. 



Fresh water: Hungary, fossil (Grun.). 



Var. excisa Grun. (1882). — Smaller. Ventral margin indented. — Grun. Foss. D. Osterr. 

 Ung. PL XXIX f. 27. Pant. Ill PL I f. 11. 



Fresh water: Hungary, fossil (Grun.). 



C. austriaca, which seems to inhabit the alps only, is characterized by its median line, being 

 oblique and therefore broad in the middle between the central and terminal nodules, by its dis- 

 tinctly punctate strise and non-rostrate ends. It is evidently akin to C. leptoceros. Cymb. Erdoben- 

 yana Pant. (II p. 40 PL XI f. 198; 1889) agrees completely with C. austriaca, as I have convinced 

 myself by examining specimens from Erdobenye. 



16. C. Stodderi Cl. (1881). — V. slightly asymmetrical, narrow, lanceolate, with subrostrate 

 ends. L. 0,o7 5 to 0,09; B. 0,oi5 mm. Median line almost central, straight; its terminal fissures 

 approximate to the ends. Axial area moderately broad, linear-lanceolate, not abruptly dilated 

 around the central nodule. Strise strongly radiate in the middle, 10 or 11 (middle) to 12 (ends) 

 in 0,01 mm., not distinctly punctate. — Cl. N. R. D. p. 5 PL I f 5. Cl. M. D. N:o 212, 274. 



Fresh water: Monmouth (Maine), Bemis Lake ("White Mountains)! Caldas (Brazil)! 



