A quick google search will show you how to ID whether male or female. Here's a snippet I took from a random answer site:
"Look at the underside of the fish. About two-thirds of the way along its body (towards the tail) will be two small fins called the pectoral fins. Slightly behind them is the anal opening, and behind that is another fin. When the fish relaxes and hangs in the water it can be sexed by means of that fin. If the fish is female, when she is relaxed, the fin will hang down in a triangle with the point down-most. All females have this fanned fin, but when it is tucked up it can look quite like a male's.
The male's fin is straight, fairly long and points directly backwards. This modified anal fin is called a gonopodium."
From what I saw in the pics, it LOOKS like your dalmatian is male, but that's only a snippet. If you can't figure it out I'd suggest starting a new thread with a few pics of each and ask the experts on here. Good luck!
It seems disappointing at first when you realize you can't have as many fish as you wanted, but you'll become more attached to those you do have and you'll take care of them even more!
P.S. I realize most this advice had been passed on already, but it never hurts to have more opinions.
I agree with rehoming the mollies, get 5-6 corys (I love peppered..it'll remind you of dalmatian molly a bit!) and some nano fish. Plenty of activity and fun to watch fish.