sentences:  De Camp revised the story slightly for its inclusion in "Rivers of Time" to update obsolete paleontological terms and dated references.In one instance the result was unfortunate; in the original version of the story, Rivers estimates Seligman's weight in both pounds and stone; in the revised version both measures are rendered as kilograms, resulting in Rivers appearing to make the same calculation twice.Many years after writing the story, de Camp penned eight more tales of its protagonist, time-traveling hunter Reginald Rivers; all nine stories were then collected as "Rivers of Time" (1993).