Introducing my dog to my kitten? helphelphelp?

I just recently got a lovely little maine coon kitten. a very sweet little thing. i also have a very large, very rowdy 1 year old catahoula leopard hound crossed with chocolate lab. hes a very good dog, very friendly. but hes such a klutzy oaf, and gets very rough when he plays with other dogs, i always tell him to settle down when he gets too rough. but anyway, i introduced them and as i expected he immediately wanted to play with it. i asked him to lay down and placed the kitten down beside him. at first he sort of snuffled him and seemed very interested, wagging his tail and all. as the kitten walked around, he followed him. keeping a very close eye on him, his eyes were locked on him and everytime the kitten made a move to go run somewhere he would jump forward as if to chase him but i would snap at him and he would stop and continue to follow him around and just stare him down. im so worried that hes gonna just go for him when im not looking. i would never trust him with him but like if he got out and i didnt know im not sure if he would do anything. what do i do ??