Patty was consulted only in regard to her own costume for the occasion.
"You see," said Nan, coming into Patty's room one morning, "I don't know whether you would rather say good-bye to your friends in the guise of a kelpie or a pixy or a jelly-fish."
"Cut out the jelly-fish," said Patty, laughing, "for they're horrid, floppy old things, I'm sure. As to the others, what's the difference between a kelpie and a pixy?"
"Oh, a great deal of difference," declared Nan, wagging her head wisely; "a kelpie is an imaginary water sprite, you know, and a pixy is a—a—why, a sort of make-believe fairy who lives in the water."
"Well, I'm glad that you see a difference in your two definitions. For my part I don't see anything to hinder my being a kelpie and a pixy both, even if I'm not twins."
"Well, they're not so very different, you know. One is a kelpie, and one is a pixy; that's about all the difference."
Patty laughed. "Well, if it will help you out any to have me make a choice," she said, "I'll choose to be a kelpie. What's the latest thing in kelpie costumes?"
"Oh, it will be lovely, Patty! I'll have it made of pale green silk, with a frosted, silvery, shimmering effect, you know, and draped with trailing green seaweed and water grasses."
"Lovely!" agreed Patty. "And what would the pixy costume have been, if
I had chosen that?"
"Just the same," confessed Nan, laughing; "but it's easier to have something definite to work at. You can wear my corals, Patty, and, with your hair down, you'll be a perfect kelpie."