BIIIANG 



TILL K. SV. VET.-AKAI). HAXDL. BAND 1. X:0 13. 9 



are notliing but forms of one and the same species, as I havo 

 scen in a rich collection of these two forms from Cuxhaven 

 intermediatc forms. (Pl. I fig. 2 a — -/). They rcsemblc eacli 

 other exactly in all important cliaracteristics, but differ only in 

 the outline which is also sometimes quadratic. The same may be 

 the case with Trlceratium contortnm Shadb (T. M. S. II, pag. 15, 

 Pl. I, fig. 7) and Biddalplda indka PiOPEH (T. M. S. VII, pag. 

 16, Pl. II, lig. 20 — 22). To make distinct genera of the forms 

 with triangulär and oval outlines is tantamount to separating 

 the two species of Hydrosera Wallicii into different genera 

 and to separating Entogor.ia Grev from Ilelhergia Grev. The 

 great difficulty in arrauging the many forms of Angulifcrse and 

 Biddulphiaj in wellfounded genera depends upon the fact, that 

 most spjecies are but imperfectly known and only from the S. V. 



20. Zygoceras Balaena Ehb {BidduIpMa Bålarna BriCxHTW 

 M. J. VII, pag. 18, Pl. IX, fig. 15 a — 15 b. Zygoceros radiatiu^ 

 Bail Smiths. Cont. vol. VII ■ 1853, Pl. II, fig. 29. Perhaps 

 the same species as Triceratium arcticum). Spetsheo-gen com- 

 mon ex. gr. AVaijgats Ids. (60 fath.) Schoal Point. Greenland 

 very common. Finmarken Grötsund. 



Found besides: Cornwallis Id. (Lat. N. 75° Brightw) Ha- 

 lifax Nov Scot. (Bail) Baltic!! (Schiiinaiui). 



21. Biddulphia aurita (Lyngb) Bréb {Sm Syn. II pag. 49 

 Pl. XLV, fig. 319). Spetsbergen very common Finmark. Green- 

 land verv common. Bavis Strait floating on the surface of 

 the sea (Lat. 32' 36' Long. 52' 50' Th. Fries). This species 

 oceurs abundantly in all seas. 



In one specimeu from Greenland I have observcd a 

 sporangial frustule (Pl. I, fig. 3 a och b). The large exteriör 

 cell measured 0,0 6 6 m.m. in hcight and 0,044 m.m. in breadth 

 and the included cell was about lialf the size of the exteriör, 

 which it rcsembled in all its characters. Both figures are taken 

 from one and the same specimen in two different positions 

 to show that the small cell was really enclosed in the large one. 



22. Biddulphia Rhombus Ehb (Sm Syn. II, pag. 49, Pl. 

 XLV, fig. 320). Sjtetsbergen only one specimen in the deposit 

 from Kings Bav (160 fathoms) Finmarken Grötsund, rare. 



?23. Biddulphia turgida (Ehb) Ralfs (in Prit Inf. 1861, 

 pag. 849. Bidd. gramdata PiOPER, T. M. S. VII pag. 13, Pl. 



