138 



Fig. 22. Monotrypa amplectens. (fib) Shell of Spirifer granulosus with Aulopora 

 tubceformis attached to it, the whole overgrown with Monotrypa amplectens, the calices 

 of the Aulopora appear like craters above the surface of the Monotrypa colony— natural 

 size ; (b) a portion of the surface enlarged, showiiiK the laiyer c-mallites of the monticules, 

 x8; (c) a portion much enlarged, showing a buried branch of the Aulopora ; (d) a calyx of 

 Aulopora enlarged, showing the relation of the Monotrypa to it. x 8 ; (e,/) sections show- 

 ing specimens enclosing a branch of Ceratopora, also showing tabula', x .">. (Original.) 



