12 INTRODUCTION. 



3. Echinodermata.— (Spiny skin) radiating in mostly 5 directions, with 



a calcareous dermal skeleton. 



4. Vermes.— Bilateral, without jointed appendages. 



5. Arthropoda. — Bilateral, with jointed appendages. 



6. MoLLUScoiDiE.— Bilateral, unsegmentecl animals, with tentacles or 



spirally rolled buccal arms. 



7. Mollusca.— Bilateral, soft, unsegmented, without a skeleton for 



locomotion ; either bivalve or monovalve. 



8. Tunicata. — Bilateral, unsegmented animals, with sac-shaped or 



barrel-shaped bodies. 



9. Vertebrata. 



In the latest important work, The Standard Natural History 

 (1885), in six large volumes, by the leading American biologists, all 

 the great naturalists of the day have been compared and are 

 quoted. In it are given nine Divisions or Branches, with a 

 prospective tenth, the Protista, those very primitive forms in 

 which animal and vegetable life are so blended that it is scarcely 

 ' possible to distinguish the one from the other. 



Branch I. Protozoa. 



II. Poriferata. — Sponges. 

 III. Ccelenterata. — Jelly-fish and corals, hydroids, or plant-like 



animals of beautiful forms (Zoophytes). 

 IV. Echinodermata. — Star-fishes, etc. 



V. Vermes. — Of which the annelids are the highest type ; seg- 

 mented or jointed worms and leeches. 

 VI.'MolluscoiD/E. — Including Polyzoa (many animals in colonies) 



somewhat plant-like, and often mistaken for seaweeds. 

 VII. Mollusca. — Shell-fish, etc, 

 VIII. Arthropoda.— Jointed legs or "foot-stalks." Insects, and 

 the Crustacea. 

 ,, IX. Vertebrata. 



The foregoing tables show us that later scientific research has 

 led to sub-divisions of certain types or groups, so that Cuvier's 

 four have been more than doubled. For example. Insects and 

 Crustacea (with jointed limbs) are separated from the worms and 

 leeches ; and instead of being only a class of the extensive sub- 

 kingdom Annulosa are now the " Branch '' or Sub-Kingdom 

 Arthropoda. Having, however, the "ringed," "jointed," or 

 '' segmented " bodies as well as appendages, they are, as Kirby 

 tells us in his Introduction to British Butterflies, " called variously 

 Arthropoda, Annulosa, or Articulata ;" the latter word having 



