 Why was each inhabitant of the moon-town only referred to as their specific species rather than a distinct name?
As though there were but one city, if that is its form. And it was for this reason also that the owners of Little Probe had acquired the original machine so cheaply. On Earth it had read Positive on a number of crack-pots, including Waxey Sax, a jazz tootler who could not even read music. Dawn did not come to the moon-town. The Little Probe hovered stationary in the light and the moon-town came up under the dawn. And those two ... why, they could well be Earth-people. And one could only wish that all people were like them. There was a man and a woman, and they were clothed either in very bright garments or in no garments at all, but only in a very bright light.
 There was only one of each, therefore, they were called by their species.
 They were all distinct by their light, and only needed to be referred to as their species.  The population was much too large to name each creature.  The humans of moon-town felt no need to waste time in naming each living creature as they died off too quickly.  There was only one of each, therefore, they were called by their species.