well you have two options, one is back breaking, the other wallet breaking. The first option is to drag a wheelbarrow or a large plastic mixing tub into the basement. Then you'll have to carry bag after bag after bag of ready mix into the basement where you can mix each bag by hand with a shovel and then apply it to the floor. This will take forever to do if the basement is large and you'll have a hard time getting enough concrete down in a quick manner to allow you float it before it starts to dry. Actually you'll pay more for the concrete if you buy it by the bag so this way will be both labor intensive and costly. The second and easiest way would be to call your local concrete company and have them pump the concrete into the basement through a window. If you don't have any windows then it might be easier to dig down around the foundation a little and cut a square out of the wall that is easiest to get to from the outside to allow a place for the concrete pumper to access the basement. Just out of curiosity why was the floor dug up in the first place?

You should try digging down a bit deeper on the edges & running rebar completly around the walls. then rent a rotohammer & carefully drill holes into the wall. this should make up for the lack of a footer for your house & help prevent any problems that will cause in the future. Just make certain that your footer is heavy enough to suport your house.