16 CLASSIFICATION. ' ^ 2. 



THIRD GROUP. 



VERMES. 



Animals with an elongated, symmetrical body, and whose organs are 

 arranged along a longitudinal axis ; so that right and left, dorsal and 

 ventral aspects may be indicated. 



The central nervous mass consists of a cervical ganglion, with or with- 

 out a chain of abdominal ganfjlia. 



Class VI. Helminthes. 

 Class VII. Tcrbellarii. 

 Class A'^III. Rotatorii. 

 Class IX. Annulati. 



FOURTH GROUP. 



MOLLUSC A. 



Animals of a varied form, and whose bodies are surrounded by a fleshy 

 mantle. The central nervous masses consist of ganglia, some of which 

 surround the oesophagus, and others, connected by nervous filaments, are 

 scattered through the body. 



Class X. Acephala. 

 Class XI. Cephalophora. 

 Class XII. Cephalopoda. 



FIFTH GROUP. 



ARTHROPODA. 



Animals having a perfectly sj^mmetrical form, and articulated organs 

 of locomotion. The central masses of the nervous system consist of a 

 ring of ganglia surrounding the oesophagus, from which proceeds a chain of 

 abdominal ganglia. 



Class XIII. Crustacea. 



Class XIV. Arachnida, 



Class XV. Insecta. 



BIBLIOGRAPHY. 



§2. 



Besides the various ancient and modern works upon general comparative 

 anatomy, — such as those of Blumenbach,'^^ G. Cuvie?-,^-' F. Meckel f' E. 

 Home,^*^ BlainvUle,'^^ Delle Ckiaje/'* Cams, ^''Gr ant, ^^^Rymer Jones, '^^ Strauss 



' Handbuch der vergleichenden Anatomie. Got- •'» De I'Organisation des Animaux, ou Princii>«s 



tingen, 1824. d'Anatomie comparte. Tom. I. Paris, 1832. 



2 Lerons d'Anatomie comparee. Paris, 1799- <' Istituzioni di Auotomia e Fisiologia Comparata. 

 1805. TraDslated into German and published with Napoli, 1832. 



notes and additions by il/fcAe/ and FroriV/). 4 vols. 7 Lehrbueh der vergleichenden Anatomie. 2iid 



I^ipzig, 1809-10. 2nd edit. Paris, 1835-45. ed. Leipzig', 1834. 



3 System der vergleichenden Anatomie. 6 vols. * Outlines of Comparative Anatomy. London, 

 Halle, 1821-133. 1841. 



4 Ijectures on Comparative Anatomy. 6 vols. '•' A General Outline of the Animal Kingdom, and 

 London. 1814-29. Manual c.f Conipanuivc Anatomy Loudon, 1841. 



