280 ON THE CLASSES OF THE 



The Amielides for the most part are aquatic animals, 

 and are all fond of moisture. They appear to be low in 

 the scale of intelligence, because, with very few excep- 

 tions, they want the head and consequently the principal 

 organs of sense. They are destitute of any members or 

 limbs for locomotion except setiferous retractile mammuke 

 which many possess, disposed in lateral rows, and which 

 serve for feet. Their mouth varies excessively in its con- 

 struction, being sometimes a proboscis furnished with 

 maxillae, as in the Nereidcz Sav., sometimes presenting the 

 appearance of two lips, as in the Serpulida and Lambri- 

 cida, and at others, as in the Hirudinidce, forming a pre- 

 hensile cavity supplied with parts which perform the 

 office of maxillae. That remarkable character of the Ver- 

 tebrata, the vertical movement of the maxillae, remains 

 still, in some measure, observable in many of the Anne- 

 lides: but what particularly distinguishes the two groups 

 from each other is the nervous system of the latter, which 

 is very distinct, longitudinal, double and knotted, like that 

 of insects. The Hirudinidtz carry this similitude so far 

 as even in general to possess the same number of ganglions. 

 Another remarkable analogy is that which the vesicular 

 branchiae of some Amielides bear to the vesicular trachea? 

 of many Annulose animals. That the Annelides thus ly- 

 ing between the two most perfect forms in Zoology, the 

 Vertebrated and the Annulose, should be so inferior in the 

 senses and powers of locomotion to both, is certainly very 



perceive that I have drawn plentifully. — The first is the report of MM. 

 Cuvier, Lamarck, and Latreille to the Academie Royale des Sciences on the 

 discoveries of Savigny with respect to the Annelides, and the second is a 

 Memoire by M. Latreille on the external organization of articulated un- 

 Tertebrated animals, and the relation which the Annelides bear to thei%~ 

 riapoda. 



