On the Structure and Development of Argiope. 517 



and Polyzoa so closely uiiited as to form a naturai phylum. I should 

 propose to follow Gegenbaur in making a primary class of the 

 Brachiopoda , and though in tlieir development and adult structure they 

 are widely separated from both Vermes and Mollusca, of the two classes 

 I would place them nearer to the fornier class than to the latter. 



Naples, July 1S83. 



Description of Plates 39 and 40. 



34 



