For the first time I made a transfer of Steem from Poloniex to my Steemit Wallet.
I went to my Wallet and clicked on Deposit.
Automatically without thinking I copied the above Address to send Bitcoins to.
Then I went to Poloniex to withdraw Steem from my Account. I copied the above address to the Address Line on Steemit.
WRONG!!!!! Arrrgh….
Because I want to transfer Steem and not Bitcoin to my Steemit Wallet the Steem I transferred got lost. The withdraw worked but the Steem was never deposited on my account. I will never see these steems again.
Therefore, follow this step by step guide on How to transfer Steem from Poloniex to your Steemit wallet
Update: Good News!
As suggested by 
in comments I opened a ticket with the Poloniex support.
Yes, and I have my steem back!
I am on Steemit because I have a mission
🌞 upvoting your lifetime dreams!