ZOOLOGY OF THE INVERTEBRATA

In this book I have tried to give such an account of the Invertebrata as might be useful to students in the upper forms of Schools and at the Universities, who are already acquainted with the elementary facts of Animal Biology. The volume is in no sense a work for advanced students, and hence no references to original sources have been given, and the name of the various investigators who have promoted our knowledge have been mentioned as sparingly as possible. In order to keep the book within reasonable limits, I have not described fully certain types which are dealt with in the admirable elementary text-books of Huxley and Martin, and Marshall and Hurst; but, with this reservation, I have endeavoured to describe some one example of each of the larger groups, and then to give a short account of the most interesting modifications presented by other members of the group.