In the list of "peculiar forms" some are marked with a x ; 

 these are, what I will call, ^'■cold forms,'''' i. e. Polar or Alpine 

 forms. On studying their distribution it will be seen that from 

 Zealand there is only one form, and that occurred in one sample 

 only; from Jutland, on the other hånd, 17 forms in 38 samples; 

 that is to say, in Zealand there is 1.3 of 1 per cent of the samples 

 which contains "peculiar forms," in Jutland 14.7 of 20 per cent 

 of the samples. The one sample in question from Zealand is from 

 Flommen near Soro, the localities of the Jutland samples were dis- 

 tributed as follows : — 



Ulfborg and Utofte, each with four samples; Blegso, Borris, 

 Oxhol aiid Struer, each with three samples; Baggesvogn, Fano, 

 Hanstholmen, Kandestederne, Krog So, Madum So, Skive, Snep- 

 trup and Vor Aa, each with one sample. This proves that Jut- 

 land, and specially its northern and western parts and its heathy 

 districts, still bears traces of a former colder climate. 



Remarks on some species and varieties. 



ad Navicula Tuscula Ehr. var. Strosei var. nova^ pp. 84 — 85. 

 This form which Strose (1. c.) has established as Stauroneis dilatata 

 W. Sm. and of which he has given an excellent figure, is cer- 

 tainly not a Stauroneis, but a Navicula related to the group of 

 forms belonging to Nav. Tuscula. It is somewhat more closely 

 striated and more fmely punctated than the typical Nav. Tuse. and 

 the longitudinal, undulating lines are absent, but these may dis- 

 appear in Nav. Tuscula also. By investigating preparations from 

 Kliken (from Thcm in Leipzig) I have convinced myself that my 

 specimens are identical with Strose's Fig. 28. On the other hånd 

 I am afraid it will be difficult to decide what is Stauroneis dilatata 

 W. Sm. If it is identical with Strose's Fig. 28, then, as already 

 mentioned, it is no Stauroneis, and in that case neither is it iden- 

 tical with Navicula crucicula W. Sm. to which it can be found to 

 be referred. That Staur. dilat. may possibly be identical with 

 Navicula scandinavica Lgst. (to which Gleve (Syn. II, 48) refers it, 

 but with doubt) I regard as not very probable. Nav. scand. Lgst. 

 is a saltwater form, but Strose's Staur. dilat. W. Sm. occurs in 



