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MANUAL OF ZOOLOGY 



The rest of the space is lined by a pair of folds of the body-wall, the 

 mantle-folds (Fig. 105), d. m, v. in), the edges of which are beset with 

 minute setae (s). In the space {mantle-cavity) lined by these mantle- 



folds lies a lophophore (Ip/t), usually of complicated form, fringed with 

 long ciliated tentacles, and supported in many cases by a delicate, 

 sometimes simple, sometimes complicated, shelly process of the dorsal 

 valve, the shelly loop (Fig. 104, s. I.). The mouth (Fig. 105, mth), 



