KONCiL. SV. VET. AKADEMIENIS II AM)LIN(iAK. I'.ANJ) 26. N:() 2. 171 



Fresli water: Sweden (Miilaren, Westergotlaiid, Smalaiid)! Finland (Alto)! Scot land ((ireg.), 

 Ireland! New Zealand! 



Var. anfiqua Gkun. — V. with subcapitate ends. L. 0,o32 to (),o3;i; B. 0,o(i8 mm. Stri;e 

 7 to 8 in U,()i mm., finely punctate. — C. ahn. var. ant. Grun. Foss. 1). Oster. Ung. p. 141 

 PI. XXIX f. 31. 



Fresh water: Hungary, fossil (Grun.). 



Var.? fo)isilis Pant. (18'J3). — Linear with slightly rostrate ends. L. 0,()r); 1>. 0,01 mm. 

 Central area a transverse fascia. Strise 8 to 9 in 0,01 mm. — Cynih. ahnoriiii.s var. f().ssilis Pant. 

 Ill PI. XVII f. 255. 



Fresh water: Hungary, fossil (Pant.). 



This little form is of interest as it has some resemblance to a Gomphonema, in its uni- 

 laterally dilated central area. The fig. given by Gre(jory is not as good as desirable, but there 

 can hardly exist any doubt that Gregory really meant this species. 



47. C. tlimklula Grun. (1875). — V. asymmetrical, linear-lanceolate, with rostrate ends. 

 L. 0,033 to (),()3.j; B. 0,007 to 0,oo9 mm. Dorsal margin arcuate, ventral straight, or somewhat 

 gibbous in the middle. Median line somewhat excentric, straight, with approximate central pores. 

 Axial areas indistinct; central area indistinct or on the dorsal side only. Strine on the dorsal side 

 13 (middle) to 15 (ends) in 0,oi mm., on the ventral side 14 in 0,oi mm., slightly radiate 

 throughout, finely punctate. On the ventral side of the central nodule are two puncta at tlie ends 

 of the two median striit. -- Grun. in A. S. Atl. IX f. 33. V. H. T. N:o 27. 



Fresh water: Rostock, fossil! Oxford! Tricst (Atl.), Paris, Marly (CI. M. D. 195)1 



Var. .salinaruin Grun. (1875). — V. asymmetrical, lanceolate, with subacute, not rostrate 

 ends. L. 0,o'i7 to 0,o4; B. 0,on8 to 0,oi mm. Axial area narrow, slightly dilated on the dorsal 

 side around the central nodule. Striffi 11 or 12 (middle and dorsal) to 15 (ventral) in 0,oi mm. — 

 C. salinarum Grun. A. S. Atl. IX f. 28. V. H. T. N:o 26. 



Brackish water: Bay of Finland (Dannf.), Saule (Atl.), Italy! 



C. tiuiiidula seems to connect C. amphiccpliala with C. turgidula, C. (iffinis etc. As far I can 

 see, there is no other difference between C. iumidiila and O. salinarum than the somewhat different 

 shape of the ends. The above descriptions are from original specimens in Van Heurck's Types. 



48. C. tiirgidula Grun. (1875). — V. asymmetrical with more or less rostrate, obtuse, or 

 truncate ends. L. U,o3 2 to 0,0.5; B. 0,oi to 0,oi5mm. Axial area very narrow. Striai in the middle 

 on the dorsal side 9 to 10 in 0,oi mm. at the ends about 11 in 0,oi mm. finely punctate, puncta 

 about 24 in 0,oi mm. At the ventral side of the central nodule are two small puncta, ending the 

 median stritie. — Grun. A. S. Atl. IX f. 23 to 26. 



Fresh water: Bengal (Atl.), New Zealand! Niagara falls! Porto Rico! Ecuador, Chimborazo! 

 Argentina! 



C. fury'uhda is nearly related to C. afflnis, but is larger and has 2 puncta below the cen- 

 tral nodule. 



49. C. iiHillis KuTZ. (1844). — V. more or less broad, semielliptical to semilanceolate with 

 almost straight ventral margin and slightly rostrate, obtuse or subtruncate ends. 1j. (),i)u:i to 0,04; 

 B. 0,007 to 0,0 1 mm. Median line slightly arcuate, excentric. Axial area very narrow, not dilated 

 around the central nodule. Stri;ti 10 or 11 (dorsal side) to 12 (ventral side) in 0,oi mm. a little 

 closer at the ends, slightly radiate, finely punctate. On the ventral side of the central nodule is 

 a small isolated punctum ending the median .stria. — Kutz Bac. p. 80 PI. VI f. 15? W. Sm. B. 

 D. I PI. XXX f. 250? A. S. Atl. IX f. 29, 38*; LXXI f. 28, 29. V. H. Syn. p. 62 PI. II f. 19. 

 V. H. Types N:o 26. CymJ). truncata Greg. M. J. Ill p. 39 PI. IV f. 3 (1855)? Cocconcma nanitni 

 Hantzscii Rab. A. E. N:o 1321 (1862). A. S. Atl. LXXI f. 27. Coccoii. (jildnim A. S. Atl. X f. 27. 

 Cymh. uffmis var. tumida Lagst. Spitsb. I), p. 43 PL II f. 19? 



