TEREBRATULINA. 65 



2. Peduncle. Its position. What is its use? 



3. Muscles. Those used in opening and closing the shell. 



4. Lophophore. Consisting of two elongated arms with a 

 double row of tentacles on each. 



5. Mouth. Notice its relation to the grooves running be- 

 tween the rows of tentacles on each of the arms of the lophophore. 



Brooks: Development of Lingula. Ches. Zool. Lab. Sci. Results, 1878. 

 Conklin: The Embryology of a Brachiopod, Terebratulina septentrionalis. 



Proc. Am. Phil. Soc., 41, 1902. 

 Hancock: On the Organization of Brachiopoda. Trans. Roy. Soc., London, 



148, 1858. 

 Morse: Observations on Living Brachiopoda. Mem. Bost. Soc. Nat. Hist., 



5, 1902. 



