3S6 ON THE ORDERS 



3. Second pair of maxillary feet, present. 



4. Third pair* of maxillary feet , none. 



5. First pair of true feet, none. 



6. Second pair of true feet, present, &c. 



This irregular appearance and disappearance of organs, 

 so contrary to the very object of M. Savigny's excellent 

 work, is, however, entirely removed by M. Latreille's hy- 

 pothesis, as is likewise the violence done by M. Savigny's 

 theory to that uniform principle of nature, which places 

 the eyes constantly in the head of an animal. Those who 

 have well weighed the admirable Mtmoire sur les Animaux 

 sans Verttbres, which first called the attention of naturalists 

 to these anatomical analogies, know that the author's theo- 

 ry, with respect to the Pycnogonida, would place their eyes 

 in the thorax, or atleast in that segment of their body which 

 corresponds with the thorax of insects. Now, only suppose, 

 with M. Latreille, that what Savigny accounts to be the 

 first ring of the body is nothing else than the manducatory 

 organs soldered together, or a prolongation of the pharyn- 

 geal region, and that the mandibles and palpi represent 

 the four antenna? [of the Crustacea, and the above ano- 

 malies will in a great measure disappear. Even although 

 the four antenna? may become all null in Pycnogonum, 

 we may perceive that those which seem the most readily 

 annihilated are the lateral pair, as in Phoxicholus. Thus 

 the only locomotive organs which we may regard as totally 

 lost in the Pycnogonida, are such as may be reckoned 

 immediately connected with the system of manducation 



* Dr. Leach has confined the name of Pedipalpi to this pair of maxillary 

 feet. J have thought it best, however, until we know more of the structure 

 of the mouth in the Apiropodes of M. Savigny, to term this, with the two 

 preceding pairs, pedipalpi, or maxillary feet, discriminating them merely 

 by their place. By this mode of proceeding their true Dature remains ad- 

 huc sui'judice. 



