( S3 ) 



B. PVith bivalve shells, or none. 

 4. Acephala. 



No apparent head ; Branchiae composed Hermaphrodite, 



mouth hidden in the bot- of large leaves covered 



torn or between the folds with vasculary net- 



of a two-lobed mantle work, upon or between 



containing the branchiae which the water passes, 

 and viscera. 



5. Brachiopoda. 



Mantle lobed; mouth Branchiae composed Fixed, without tl 

 exterior, between the ba- of small leaves, ranged power of locomotion, 

 ses of two long fleshy round the edge of the 

 arms supplying the place inner face of each lobe, 

 of a foot and with nume- 

 rous filaments. 



6. Cirrhopoda. 



With numerous hairy 

 filaments, in pairs, com- 

 posed of small articula- 

 tions representing feet or 

 fins, towards the orifice 

 of the shell ; mouth at the' 

 bottom of the shell. 



Ditto, 



