Why is fermentation taking so long to start?

I pitched a rehydrated packet of Danstar Nottingham dry yeast into my ~78F 1.044 OG wort about 20 hours ago and still have no signs of krausen or fermentation. I used an aquarium pump with a pumice stone for thirty minutes to oxygenate. I rehydrated the yeast according to the packet and pitched right away.

I do have a dry yeast starter I made with the nottingham yeast and decided not to use, it is sitting in my fridge -- should I pitch that on top??

 

When you rehydrated did it foam up? (proof)

 

Fermentation can take 72 hours to show visible signs. Just relax and wait.

 

Yes it foamed up -- ill try waiting 72 hours and seeing

 

When I use rehydrated Nottingham, it usually takes about 24 to 30 hours to show signs that it is fermenting. Now, cool that beer down or Nottingham will provide you with some interesting (and not in a good way) flavors. I prefer to pitch mine at 57-62 degrees.