BRACHIOPODA. 383 



been much divided. The author of ^ Conchologia Syste- 

 matica^ has, however, in accordance with his own opinion, 

 and at the suggestion of Deshayes, adopted the higher rank 

 assigned to them by Cuvier, and placed them next to the 

 Lamellibranchs. 



The animal thus wondrously constructed, and to whom 

 the means of support are granted by the aid of a curious 

 and complex apparatus, presents no external beauty. His 

 form is ovate, or oblong ; he is provided with spirally-twisted 

 arms, as before mentioned, — also with several muscles; 

 headless, he is without eyes, and has a central mouth. 



The shell is either calcareous or horny, uniformly bivalve, 

 having no hinge-ligament, but adhering firmly to the occu- 

 pant by means of muscles : it is fixed externally to rocks or 

 stones, or marine substances, either by a long pedicle or 

 short fibrous tendon, or immediately by the lower valve. 



Brachiopods include two small families, which are de- 

 signated, from their mode of attachment, Tendinosa and 

 AhhcBrentia. 



