Page:Popular Science Monthly Volume 16.djvu/826

 to reproduce one of these highly finished engravings representing the most fully developed of the crayfish's limbs (Fig. 1), and some others which give a fair notion of the excellence of the illustrations of Professor Huxley's book.

To this follows a chapter in which the English crayfish is compared in a variety of points with crayfishes of other lands, such as those of Russia (Fig. 2), of Australia (Fig. 3), and of North America (Fig. 4), with lobsters and prawns, and it is explained how the amount of likeness and difference between these various but closely similar animals



may be expressed by the method of classification in groups. Finally, we have a chapter on the geographical distribution of crayfishes, and the facts therein narrated, together with those adduced in the previous