1 84 MANUAL OF ZOOLOGY SECT. 



the first two colonial, the third solitary, which, among other special 

 features, have the anus situated within the circlet of the tentacles. These 

 are known as the EndoprOCta as distinguished from the EctOprOCta 



tent 



tettl 



FIG. 97. Pedicellina. Showing successive stages (numbered / to 6) in the develop- 

 ment of zooids by budding, an. anus ; gang, ganglion ; mo. mouth ; tent. 

 tentacles (retracted). (After Hatschek ) 



or ordinary Polyzoa, in which the anus, as we have seen, is external 

 to the lophophore and tentacles. 



3. THE BRACHIOPODA 



The Biachiopoda, or Lamp-shells, are a group of marine animals 

 which present certain features of resemblance to the Polyzoa, and on 

 that account are sometimes placed with them in a special phylum to 

 which the name Molluscoida r Podaxonia is applied. The 

 Brachiopoda are solitary, never giving rise to colonies like those of 

 the Polyzoa ; and one of their most striking characteristics is the posses- 

 sion of a calcareous shell which bears a remarkable resemblance to that 

 of the members of a widely different group, the Pelecypoda, belonging 

 to the phylum Mollusca the group to which the Mussels, Oysters, 



