4000 species known, but over 3million presumed to be living on the earth
Scientists estimate that there are more then 9,000 species of Cnidarians identified.
reasearchers have found 4000 different types of bacteria in 1 gram of soil. Their are about 5*1030 numbers of bacteria on this planet
To put this question into perspective, recent estimates say that only 1% of the species of bacteria have been identified. So, a lot. Too many to count.
It is impossible to quantify an unknown factor.