SUB-KINGDOM VI. MOLLUSCOIDEA. 



Classes. Sub-Classes. Orders. Sub-Orders. 



1. Phylactolaema. 

 1. EctoproctaJ /I. Cyclostomata. 



/ 



1. Polyzoa ....... J ^ 2 - G y mnolaem a- J 2. CheUostomata. 



2. Entoprocta. ( 3. Ctenostomata. 



V 3. Aspidophora. 



Orders. 



_ , . , II. Inarticulata. 



2. Brachiopoda. ^ _ 



(2. Articulata. 



WHETHER the two classes Polyzoa and Brachiopoda are 

 very closely related to one another is rather doubtful. 

 They have affinities on the one hand with the worms and 

 on the other with the mollusks. For the present they 

 may be retained as a separate sub-kingdom. 



CLASS. POLYZOA. 



With the exception of the genus Loxosoma, all the 

 Polyzoa are colonial animals, numerous individuals living 

 in association. The colony may be arborescent, laminar, 

 almost massive, or encrusting shells and stones. A dermal 

 skeleton, consisting of calcareous or chitinous material, is 

 usually present. The entire colony is known as the 



