PROTOCHORDATA 



591 



Fig. 443. Ciona intestinalis. From Shipley and MacBride. The Hve animal 

 seen in its test; some of the organs can be seen, as the test is semitransparent. 

 An. anus; at. atrial orifice; hrn. brain; g. reproductive organs; g.op. genital 

 openings; int. intestine; M. mouth; m. muscles; pph. peripharyngeal ring; 

 St. stoma9h; stk. stalk attached to a rock; ten. tentacular ring. 



