CONTENTS. 



PAGE 



PROTOZOA, . . . ! 



SPONGES, 39 



HYDROZOA, . 57 



PLANARIANS, 77 



NEMERTINES, 83 



ROTIFERA, . 89 



MOLLUSCA, . 95 



POLYZOA, 169 



VERTEBRATA, 173 



TUNICATA, 185 



