ANATOMY OF THE CI. A}!. 





Fio. 72.— A. Mya armaria with its siphons extended ; h 



the mud head-end downwards; a, trai stion "t" the >h>-:i ,.f r 



showing the position of the spring opening; the shell; M 



the ligament represented by the dark mass; of Mya ■ the 



ition of the spring to "pen the shell; /.. ligament; /'. tr.u- 

 of 1'nio uifier Brooks ventricle; /.intes- 



tine; t. glandular part of kidm ii-glauduiar part vi kidney; y, sinus 



venosus; ig, inner, eg. outer, gills; to, mantle. 



