BRACHIOPODA. 



433 



in deep water, hanging from shelving rocks and from 

 coral hanks. Some kinds, as Lingnla, are found living on 

 or in the sands, in shallow water. 



FIG. 662. 



Lingula anatina, Lam. Reduced. Philippines. 



There are nearly a hundred living species ; and more 

 than twelve hundred species have been found in the rocks, 

 from the Silurian to the Present. 



Fio. 663. 

 Ventral valve. 



a 



A 



Dorsal valve. 



Muscular system of a Brachiopod Tfrf.bratula. 



a, adductor muscles; v, cardinal muscles; x. accessory muscles; /), ventral ped- 

 icle muscles; ]>', dorsal pedicle muscles; z, capsular muscles ; o, mouth; v, vent; 



2, loop; t, dental socket. 



FIG. 664. 



Dorsal valve Ventral valve. 



Fossil Brachiopod Spirifera striata, Sowerby. The dorsal valve, showing spiral 

 processes for the support of the oral arms. 



