392 



COLLEGE ZOOLOGY 



FIG. 339. Diagram of the metamorphosis of the free, tailed larva into 

 the fixed Tunicate. A, stage of free-swimming larva. B, recently fixed larva. 

 C, older fixed stage, atr, atrial cavity; cil.gr. ciliated groove on wall of 

 pharynx; end, endostyle; ht, heart ; med, trunk-ganglion; n.gn, ganglion; 

 wo/o, notochord ; or, branchial aperture; reel, intestine; sens.ves, sensory 

 vesicle ; stig, gill-slits ; stol, shoot from which buds rise ; /, cast cellulose 

 envelope of tail. (From Davenport, after Seeliger.) 



