viii ROTIFERA, POLYZOA, AND BRACHIOPODA 



185 



opposite end as anterior. The two valves articulate together by a more 

 or less distinct hinge situated at the posterior end, and the movements 

 of both opening and closing of the shell about this hinge are effected 

 by means of muscles passing internally between the valves. 

 ,b *« 



/- 



d.-rrf 



culm 



Fig. 104. — Magellania flavescens . A, the entire shell from the dorsal aspect ; B, 

 from the left side ; C, interior of ventral valve ; D, of dorsal valve ; ad. m t adduc- 

 tor impressions ; b, beak ; c. p, cardinal process ; d, deltidium : d. m } divaricator 

 impressions; d. v, dorsal valve ; J", foramen; p. m, protractor impressions; 

 s, tooth-socket ; j. /, shelly loop ; sp, septum ; t, tooth ; v. v, ventral valve. 

 Australian seas. (After Davidson.) 



The body of the animal occupies a relatively small part of the space 

 contained in the interior of the shell and lies toward the posterior end. 



