I HAVE just read with much interest the paper in NATURE by Mr. W. Saville Kent, criticising my friend Carter's article in the “Annals of Natural History” for this month, in which I fully concur.

The simple Marine Sponge (Grantia sp.). This sponge is a marine animal, found commonly along the Atlantic coast of the United States.” But we can recommend the little book as a terse, ...