Please add spaces between words: Soitiswithmostoftheinhabitantsoffreshwater,formanyofthegenerainthemostdistinctclassesrangeovertheworld,andmanyofthespecieshaveenormousranges.
So it is with most of the inhabitants of fresh water, for many of the genera in the most distinct classes range over the world, and many of the species have enormous ranges.