Unidentified dinoflagellate

I´ve found a dinoflagellate that I can´t put a name on. I first found it in a channel in Landskrona in mid June, with a salt water inlet. I found it later in the south of Öresund from mid July. Always with two spines.

I think I can see 3 spines one that is between the two that are truly visible?! The third one is close to the left one but a little fuzzy maybe from being out of focus. Maybe this is not true but I do think that if it has three spines I could name it but not untill I am wotk as I do not remember the name....

The dinoflagellate is very similar to a freshwater species complex, Peridinium umbonatum. This species is also observed in brackish water with low salinity.